Third-instar Oestrus caucasicus larvae (n = 236) obtained from Iberian ibex, Copra pyrenaica, were reared in a laboratory to obtain adult flies. They were maintained at a temperature of 21.9 +/- 2.7 degrees C and a relative humidity of 38.9 +/- 8.0 %. In all, 78 imagos emerged (33.1 %), with a sex-ratio at emergence not differing significantly from 1:1; 25 larvae did not complete pupariation. A total of 14 adult flies (17.9 % of the adults obtained) showed malformations, mainly in their wings. The pupariation period lasted around 30 hours and the pupal stage lasted on average 29.8 +/- 6.8 days. The success of pupation in both sexes was mainly determined by the weight of the larvae. Sexual dimorphism, with higher weights in females, was evident in third-instar arvae, pupae and adults. The mean longevity of adult flies was 224.8 +/- 91.4 hours and males generally survived for onger than the females.