Seeds of Albizia procera were treated with 5 concentrations of ethyl methanesulfonate (EMS) viz. 0.10, 0.25, 0.50, 0.75 and 1.0%, in pre- and post-irradiation combination with an 80 kR acute dose of gamma rays at two moisture levels. The mutagenic effect was assessed on the basis of reductions observed in germination, seedling survival and seedling growth and biomass. Anaphase bridges and laggards were observed in mitotic divisions and the number of abnormal cells scored. Germination value and root length were most sensitive to treatment and presoaked seeds were more sensitive. The pre-irradiation treatment with EMS was more effective than the post-irradiation treatment, since this caused greater reductions in most of the parameters measured.