This paper deals with a faunistic survey of Ichneumonidae (Hymenoptera) collected from some regions of three provinces, Alborz, Guilan and Qazvin in northern part of Iran. In total, 66 species in 47 genera and 13 subfamilies were collected and identified: Acaenitinae (two species, two genera), Anomaloninae (two species, two genera), Banchinae (six species, six genera), Campopleginae (six species, three genera), Cremastinae (three species, two genera), Cryptinae (eleven species, seven genera), Ichneumoninae (three species, three genera), Mesochorinae (five species, two genera), Metopiinae (eight species, four genera), Orthocentrinae (five species, five genera), Phygadeuontinae (two species, two genera), Pimplinae (five species, four genera) and Tryphoninae (seven species, five genera).