A 0.5 g/l suspension of silica particles (range 0.2-8.0 mu m) in water was microfiltered in a Millipore 0.2 mu m unbaffled tubular ceramic membrane. The crossflow was varied periodically at frequencies inducing fluid-dynamic unsteadiness using a collapsible-tube pulsation generator. The time-averaged Reynolds number at the membrane inlet was 1340. The time-averaged transmembrane pressure, (P) over bar(tm), was systematically varied from 70 to 180 kPa With pulsation the filtrate flux reached a plateau faster than in steady how at the same (P) over bar(tm), and time-averaged crossflow velocity. The flux enhancement (pulsating-flow flux/steady-flow flux) increased with increasing (P) over bar(tm), reaching 450%.