Predator selectivity for age and sex classes has large implications for their impact on prey populations. We examined whether the Eurasian lynx Lynx lynx selects specific sex and age categories of roe deer Capreolus capreolus, and if this selection pattern differs between summer and winter. Data on sex and age of 194 roe deer killed by 44 VHF- and GPS-marked lynx were collected in southern Norway from 1995 to 2010. The sex and age distribution of the roe deer population was estimated using demographic parameters estimated from radio-collared roe deer in the study area. We found that lynx selection differed between summer and winter. In both seasons, lynx selected adult roe deer of both sexes. In summer, there was a clear selection against yearlings, but in winter, lynx selected male yearlings. Compared with the availability, fawns of both sexes were under-represented during summer. Male and female lynx did not differ in their prey selection, but yearling lynx tended to kill a larger proportion of roe deer fawns than older lynx. We argue that seasonal differences in behaviour, activity and habitat use by roe deer may explain this variation in lynx selection patterns, supporting the view that prey selection is affected by the life cycle stage of both the predators and the prey.