The antiviral effect of 22 acridine derivatives was studied on the multiplication of herpes simplex virus type 2 (HSV-2) in Vero cells. The inhibitory effect of four acridine derivatives on the multiplication of HSV-2 is emphasised, six other compounds have moderate activity and three only slightly affect the virus multiplication, while nine compounds are inactive. Some of the effective derivatives inhibit the virus replication without any direct effect on the virus particles. However, the mechanism of the antiviral effect is still not known.