A partial account of the results of a study of cave-dwelling spider fauna of Kohgiluyeh & Boyer-Ahmad and Fars Provinces, in southwestern and southern Iran, is presented. Ten caves were investigated, about 75 spider specimens were collected and 11 species were identified, of which, Metellina orientalis (Spassky, 1932) (Tetragnathidae) is recorded for the fauna of Iran for the first time. Maps of localities are provided and the male of the newly recorded species is illustrated.