Europe's largest drugmaker by market value posted sales of 10.9 billion Swiss francs ($10.9 billion), short of the 11.45 billion which had been expected according to a Reuters poll of 19 analysts.
"Now the question is how many negatives have already been priced into the stock price," a trader said, referring to Roche's recent share price decline on expectations of weak first-quarter sales.
The stock has lost a third of its value since peaking at 241.4 francs in early 2007.
Many pharmaceuticals makers face slowing earnings growth due to the loss of exclusivity on key drugs, pricing pressures and more complicated paths to market.
Basel-based Roche, which confirmed its full-year earnings forecast, has so far been able to avoid the worst of the sector's troubles, though analysts had expected its first quarter to be hurt by the weak dollar and previously flagged a loss of sales of flu drug Tamiflu for government stockpiling.
"Obviously, they've been impacted by Tamiflu but they have reiterated their guidance," said Collins Stewart analyst Navid Malik, who rates Roche a "buy."
"It's not an easy market and they have suffered heavily from the strength of the Swiss franc, but I think the underlying growth is there, particularly from the oncology products -- there is always quarterly phasing with these products," Malik said.
Roche's total drugs sales rose 1 percent to 8.57 billion francs. Revenue was 9 percent higher when pandemic sales of Tamiflu were excluded.
Tamiflu sales fell 64 percent to 278 million francs, hit by the loss of orders from governments for stockpiling in case of an influenza pandemic.
Loss of pandemic Tamiflu sales would cost 1.7 billion francs in sales in 2008, Roche's drugs chief William Burns said, confirming a previous forecast.
Sales of Roche's key cancer drug Avastin rose 35 percent to 1.13 billion francs.
But growth rates of both Avastin and another important cancer medicine, Herceptin, were slower than in the previous quarter.
The weak dollar also hurt Roche's sales -- which fell 4 percent in Swiss francs versus a 2 percent rise in local currencies -- but Chief Executive Severin Schwan said the company was hedged against some of the impact because of its sites in the United States.
Roche trades at about 12 times forecast 2009 earnings, a premium to other large-cap European drugmakers thanks to its promising new drugs, limited exposure to generic competition and profitable partnership with U.S. biotech company Genentech .
That compares to a multiple of 11 for local rival Novartis and is even further ahead of GlaxoSmithKline at 10, AstraZeneca at nine and Sanofi-Aventis at eight times forecast 2009 earnings.