A microearthquake survey was conducted in Kenya from December 1969 to March 1970. The recorded activity was confined to the rift system, and, in the main eastern rift, the activity was greatest in the south and decreased northward. Approximate locations of earthquakes showed that activity was not restricted to a central zone in the rift but was scattered throughout it. Depths of focus were shallow—less than 15 km. The most active region was in the Kavirondo rift near the site of a series of earthquakes in March 1968; microearthquakes were concentrated in a very small region approximately 3 to 4 km deep and in a region with dimensions less than 2 km. The locations support the interpretation that these events reflect movement on the Lambwe fault.