Four new species of Lasiodiplodia; L. citricola, L. gilanensis, L. hormozganensis and L. iraniensis from various tree species in Iran are described and illustrated. ITS and partial translation elongation factor 1-α sequence data were analysed to investigate their phylogenetic relationships with other closely related species and genera. The four new species formed well-supported clades within Lasiodiplodia and were morphologically distinct from all other known species.
