Tried to establish the duration of phases in the imbibition process of oil radish seeds. Seeds of cultivar CATI AL-1000 lot of 2004, and the cultivars IPR 116 lot of 2004 and 2005 were soaked in "gerbox" box, under moistened paper in B.O.D. adjusted in temperature 25°C, with four replications of 50 seeds. Was calculated the percentual increment of mass over the time, in function of initial mass in the intervals of time of 15 minutes, 2 hours, 4 hours, 6 hours and 12 hours. The research was conducted in two experiments, the first with the same sample of seeds in the weighings and the second with different samples. In 1° experiment, the cultivar CATI AL-1000, ended the phase I with 28,55 hours and the phase II with 35,87 hours. Cultivar IPR 116 ended the phase I with approximately 18,05 hours for the lot of 2004 and 21,32 for the lot of 2005, beginning from this point, the phase III. In the 2nd experiment, seeds of cultivar CATI AL-1000 concluded the phase I with 49,07 hours and the phase II with 116,93 hours. For seeds of cultivar IPR 116, lots of 2004 and 2005, was not verified the phase II of imbibition, being the phase I finalized with 52,55 hours for the lot of 2004 and 152,78 hours for the lot of 2005 with the germination of seeds started after this period