The effect of 2-isopropoxyphenyl methylcarbamate (Unden) (10- or 30-day exposure) on the selected parameters of humoral and cellular immunological response in mice was investigated. Hematologic and histologic examinations were run parallelly. It was noted that this compound exerts immunotropic effect. Immunosuppressive effect was prevailing (PFC, GvH, humoral response to SRBC) but in some tests also stimulatory effect was observed (number of B cells, Il-1, stimulation and proliferation of reticular cells were also observed in the spleen and lymphatic nodes). Immunotropic effect of Unden was reversible - after the exposure to pesticide had been stopped, the investigated parameters of the immunological system activity (PFC, IgG, IgM) spontaneously came back to the norm.