Quarterly revenue fell to $21.71 billion from $24.50 billion a year earlier, the company said on Monday. That compared with analysts' average forecast of $22.56 billion, according to Reuters Estimates.
Net profit for the quarter ended March 31 fell 1 percent to $2.30 billion from $2.32 billion in the year-ago quarter.
Profit per share, however, rose to $1.70 from $1.64, as the number of shares outstanding decreased.
International Business Machines Corp has fared better than many other technology firms, thanks to its growing focus on software and services, such as outsourcing and technology support.
(Reporting by Ritsuko Ando; Editing by Richard Chang)