This study aims to analyze factors causing increased of dryness phenomenon on small rivers in Prut basin. Are analyzed, the non-climate components of the landscape (relief, geology, soil, vegetation) and climatic factors on corresponding area (rainfalls). In reporting the number of years that has occurred dryness to number of years of observations showed that the frequency of the dryness phenomenon is over 90% for basins with areas less than 5 km2. The maximum period recorded without flow for small rivers in this basin was 292 days in 1987 on Ciurea hydrometric station closing Tinoasa catchment (A = 4.71 km2) and 326 days on Humăria hydrometric station (A = 1.65 km2) in the same basin. Should be noted the role of factors determine increasing phenomenon, namely geology (groundwater un-interception) and wooded areas (if smaller quantities of precipitation).