A new Fritillaria species, F. atrolineata, is described from Iran. The new species, an endemic to Western Azarbaijan, belongs to the F. caucasica group, sect. Olostyleae, subgenus Fritillaria. SEM studies of nectaries, stamen, pollen and styles are presented. Differences from other Iranian species in the Caucasica group are discussed. The chromosome number is 2n = 24.