Dividend stocks should ideally be buy-and-hold investments that you can forget about in your portfolio. You shouldn't need to constantly check on those businesses to see if their payouts are safe or if their dividends look sustainable. If you do, that's a sign that perhaps you've picked stocks that are too risky. 

Cardinal Health (CAH -0.64%) and Cisco Systems (CSCO 1.51%) are two high-yielding dividend stocks that you won't need to worry about in your portfolio.

1. Cardinal Health

What makes Cardinal Health a safe stock is that it's in the business of distributing medical and pharmaceutical products. It isn't a risky biotech stock, nor is it dependent on a single product. It has a broad reach, serving almost 90% of U.S. hospitals and 60,000 pharmacies.

Although the company's margins aren't typically high, its sales volume helps make up for that fact. In its fiscal 2022, which ended June 30, revenue rose 12% to $181.4 billion. The company incurred a net loss of $932 million, but that was largely due to a goodwill impairment charge of $2.1 billion on its medical segment as a result of inflation, higher interest rates, and supply chain constraints.

During the fiscal year, the company generated $2.3 billion in adjusted free cash flow -- more than four times the $559 million it distributed in dividends. For fiscal 2023, management projects adjusted free cash flow between $1.5 billion and $2 billion. Cardinal Health also expects to repurchase between $1.5 billion and $2 billion in shares. It's a great sign for investors when a company can not only continue paying its dividends but feels confident enough that it can also justify buying back its stock.

At recent share prices, the dividend yields 2.8%, and that payout looks safe. Cardinal Health is a Dividend Aristocrat as it has raised its payouts annually for more than 25 consecutive years. That gives investors extra incentive to hang on to the healthcare stock as its payouts are likely to continue increasing.

2. Cisco Systems

If you're craving a higher-yielding stock, then Cisco Systems may be the choice for you. At the current share price, it yields 3.3%, more than double the S&P 500's average yield of 1.5%. 

This isn't your typical tech stock. It trades at a modest 16 times earnings (the average tech stock trades at a multiple of 26), and it's a relatively stable company, posting revenue between $49 billion and $52 billion in each of the past four fiscal years. Cisco is known for its security products, routers, wireless systems, and other products aimed at helping companies securely connect to the internet.

In its fiscal fourth quarter, Cisco beat expectations for both revenue and profit, though its sales of $13.1 billion for the period (which ended July 30) were flat year over year. It also offered a stronger-than-expected forecast, projecting revenue to rise between 4% and 6% for the new fiscal year (analysts were only expecting growth of 2.3%). Cisco noted in its earnings release that both its backlog and product orders are at record highs.

The company's earnings per share for the fiscal year were $2.82 -- 86% higher than its $1.52 annual dividend per share. Cisco isn't a Dividend Aristocrat because it hasn't been paying dividends long enough. However, the company has been raising its payouts annually since 2012, when shareholders were receiving just $0.08 per share every quarter.

Cisco is in fine shape, and while you may not see much in the way of high growth from the business, its dividend looks incredibly safe. For income investors, this may be one of the safest tech stocks you can own.