Lanosterol is the crucial intermediate in ergosterol biosynthesis in fungi. A number of derivatives of natural or synthetic origin of these sterols are portrayed in this review. For the synthetic derivatives, strategies of their syntheses are presented. Biological activities of lanosterol and ergosterol derivatives include antimicrobial, especially antifungal action, anticancer and antiviral effects but also anti-inflammatory and anti-allergic potential. The most promising seems to be the anticancer potential of peroxides, epoxides, and keto- derivatives of both sterols.