For passive, long-term investment strategies, establishing a solid framework and asking the right questions is crucial. The goal is to identify ASX-listed dividend stocks that possess a strong defensive moat, a clear business model, a resilient balance sheet, potential for growth, and a reasonable valuation.

Here are three such stocks worthy of consideration for a passive investment portfolio.

Washington H. Soul Pattinson and Co Ltd (ASX: SOL)

Although the name is historically associated with pharmacies, the company sold its last remaining interests in that retail chain in 2020. It now operates as an investment firm with a portfolio structured for steady wealth accumulation over time.

In 2025, the company merged with building materials manufacturer Brickworks Limited, concluding five decades of cross-shareholdings. This new structure formed a $14 billion investment entity, enhancing both liquidity and transparency.

What Makes Washington H. Soul Pattinson a Reliable ASX Dividend Stock?

The company's primary defensive strength lies in its diversification across numerous uncorrelated sectors. This large-scale diversification smooths out earnings, reduces volatility, and facilitates long-term capital allocation.

Its model is straightforward: a long-standing investment conglomerate that invests in high-quality businesses to compound capital, all while maintaining a robust financial position. As of the first half of 2026, Soul Patts held pre-tax net assets of $13.5 billion, a 14.6% increase from the previous corresponding period. It also held cash reserves of $427 million, providing a buffer against potential setbacks, though its diversification offers substantial inherent coverage.

Regarding growth potential, Soul Patts invests in both listed and private companies globally, offering almost limitless opportunities. It remains a family-run business despite its size, ensuring management has significant skin in the game.

In terms of returns, the company has an impeccable record, having paid dividends every year since its ASX listing over a century ago. Furthermore, it has increased its dividend payout annually for the past 27 years.

While the stock trades at a premium, this valuation is justified for passive investors given its strong track record and high-quality balance sheet.

Cochlear Ltd (ASX: COH)

Cochlear is a global leader in implantable hearing solutions, holding approximately 60% market share in developed markets. It benefits from solid recurring revenue, as patients return for device upgrades and accessories.

What Makes Cochlear a Reliable ASX Dividend Stock?

Its high-quality, trusted healthcare products, which significantly improve lives, create strong customer loyalty, keeping patients within the Cochlear ecosystem. A global reputation and a strong position in a tightly regulated market provide a solid defensive moat. Despite recent challenges, its balance sheet remains resilient.

The business model is easy to understand, with over 1 million people worldwide using a Cochlear device. An aging population is expected to drive increased demand for hearing devices in the coming years, creating a clear growth pathway. The company is also a recognized innovator, consistently investing in research and development, positioning it to remain at the forefront as technology advances.

However, the company has faced recent setbacks, with its share price falling 37% over the past twelve months. Delays in transitioning patients to its new Nucleus Nexa device contributed to a 9% decline in underlying net profit, missing analyst expectations.

Despite this, it maintains strong cash holdings. In its first-half 2026 report, operating cash flow increased by $26.9 million to $136.8 million, and free cash flow rose by $24 million to $82.7 million.

The company recently announced a dividend of $2.15, unchanged from the prior corresponding period. While this has raised concerns about a potential end to its streak of dividend growth, a rebound is anticipated in the second half as the Nucleus Nexa rollout gains momentum.

Current conditions present an opportunity for passive investors to acquire a market-leading stock at an attractive price.

Brambles Ltd (ASX: BXB)

Brambles operates CHEP, the world's largest pallet-pooling network, supplying reusable pallets, crates, and containers globally. Its model offers a cost-effective and efficient circular logistics solution for manufacturers and retailers, and its service is widely regarded as the industry benchmark.

What Makes Brambles a Reliable ASX Dividend Stock?

Brambles possesses a classic defensive moat built on scale, network effects, and customer loyalty. The extensive nature of its services makes it disruptive and difficult for customers to replace, and the high quality of service provides little incentive for them to switch.

While global logistics is complex, Brambles' core business is simple: it rents shipping pallets to customers, then collects, repairs, and reissues them. This circular model generates largely predictable cash flows.

First-half 2026 results demonstrated a resilient balance sheet, with increases in sales revenue and underlying profit. Free cash holdings stood at US$481.7 million, up $52.5 million from 2025. The company also reported an interim dividend of US$0.23 per share, a 21% increase from the full-year 2025 dividend.

These results are particularly impressive given the current global climate, which includes demand challenges in some markets and rising cost pressures driven by inflation.

Although the stock has a moderate to high price-to-earnings ratio, this reflects its quality. With solid dividends, a wide defensive moat, and a resilient balance sheet, the current share price represents fair value for passive investors.