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CSL vs Pro Medicus shares: Which ASX healthcare stock should you buy in October?
When Aussie investors think "healthcare blue-chip", CSL Ltd (ASX: CSL) probably springs to mind. But rapid-growing tech player Pro Medicus Ltd (ASX: PME) is making waves of its own. Both operate in the fast-evolving healthcare sector, but their businesses, fundamentals and shares shape up very differently. With October upon us, here's how CSL and Pro Medicus compare for investment appeal right now.
The case for CSL
CSL is a long-established giant in global biotherapy and vaccine development, with more than a century under its belt. Its core business sprawls from treating rare diseases and producing vaccines, through to iron deficiency and kidney health, with operations in over 40 countries. CSL's key divisions include CSL Behring (plasma therapies), Seqirus (vaccines), and Vifor (nephrology), making it a highly diversified healthcare operator.
Looking at the numbers, CSL boasts a massive $87.3 billion market cap, cementing its blue-chip status on the ASX. Its price/earnings (P/E) ratio sits at 18.12, considerably lower than many growth-focused healthcare peers. A dividend yield of 2.29% and a payout of $4.05 per share will appeal to income-minded investors, though notably, its dividends are currently unfranked. For 2026 to date, the shares have delivered a positive return of 4.8%.
Interestingly, CSL's reported earnings per share (EPS) in this snapshot is negative (-5.35), which doesn't mathematically square with a positive P/E ratio. Note: CSL's reported P/E ratio may be based on a different earnings measure (e.g. underlying or forward earnings) than the EPS figure shown, which is why they may appear inconsistent.
The case for Pro Medicus
Pro Medicus is a healthcare technology company specialising in medical imaging software used by radiology clinics and hospitals. Its main products — advanced Radiology Information Systems (RIS) and Picture Archiving and Communication Systems (PACS) — help streamline image management and reporting for some of the world's top medical centres, especially in the US. The company also offers workflow optimisation, network design, and training.
While much younger and nimbler than CSL, Pro Medicus has grown into a $16.94 billion company as of the latest data snapshot. Its valuation is rich: a P/E ratio of 63.49 reflects the high growth investors expect from healthcare tech disruptors. For dividend hunters, Pro Medicus pays out a much smaller (but fully franked) yield of 0.43%, with a dividend of $0.69 per share.
Notably, Pro Medicus has posted positive EPS (2.536), but its shares have struggled this year, dropping -26.8% year to date. That underperformance stands in sharp contrast to CSL's modest gains.
Valuation comparison
Here's how CSL and Pro Medicus compare on fundamentals, using the latest available numbers:
| Metric | CSL | Pro Medicus |
|---|---|---|
| Market Cap | $87.30 billion | $16.94 billion |
| P/E Ratio | 18.12 | 63.49 |
| Dividend Yield | 2.29% (Unfranked) | 0.43% (100% Franked) |
| Dividend per Share | $4.05 | $0.69 |
| Year To Date Return | 4.8% | -26.8% |
| Earnings per Share | -5.350 | 2.536 |
Note: CSL's positive P/E and negative EPS figures may seem inconsistent; this could be because underlying or forward earnings have been used for the P/E.
Recent share price performance
Comparing recent share price action up to 28 September, here's how their shares moved heading into October:
- As of 28 Sep 2026, CSL shares closed at $181.91, gaining 2.8% on the day and advancing 4.8% year to date.
- As of 28 Sep 2026, Pro Medicus shares ended at $162.15, rising 0.7% for the day but down sharply, by -26.8% year to date.
So while CSL has trended higher in 2026 so far, Pro Medicus has seen a notable pullback despite its earlier strong run.
Which is the better buy?
If I had to choose just one ASX healthcare share for October, my pick would be CSL. Here's why: Despite a challenging couple of years, CSL offers the steadiness of a global leader with a long track record, a mid-range (for healthcare) P/E ratio, and a solid dividend yield — all with demonstrated year-to-date gains. Its scale, diversification, and staying power make it hard to look past, even allowing for some confusion around current reported earnings.
Pro Medicus is an exciting disruptor with unique tech and exposure to US healthcare, but its lofty valuation (P/E above 60) and steep share price slide this year make it tougher for me to justify at current prices. While Pro Medicus' 100% franking is a perk, its yield is modest and its short-term momentum is firmly negative.
For a mix of quality, income and market resilience in the current environment, I think CSL stands out as the better buy for October.
