The present study was conducted at the Department of Agriculture and Horticulture, ESALQ, from October 1981 to February 1982. The objective was to determine the susceptibility of pepper crop to tempora y floodings of the root system, in order to quantify yield damages in distinct phases of vegetative cycle. On the other hand, the study tries to establish the drainage coefficient, for projects utilizing pepper crop. The results showed that pepper plants are susceptible to excess of water in the soil, lowering yields through the reduction of number and weight of fruits, when submitted to 2, 4 and 6 days of flooding. The drainage time of the root zone must be less than 2 days.