In the survey of 30,000 smartphone users, Android captured 36.4 percent of the market February through April, ComputerWorld reported.
Android had surpassed iPhone in a previous survey, which covered November, December and January.
Microsoft's Windows for phones slipped in the recent survey, dropping from 8 percent to 6.7 percent of the market share.
Overall, smartphones are gaining a larger audience with 13 percent more users at the end of April than at the end January, ComScore said.
Research in Motion, makers of the BlackBerry, found its market share down 5 percentage points to 2.7 percent of the market in the latest survey.