The aim of the present study was to retrospectively analyse the effect of age at the first mating on lifetime reproduction efficiency in Czech Large White (CLW) and Czech Landrace (CL) sows. Data about CLW and CL sows were obtained from breeding herds and their document registration. The average number of parities (achieved in productive life of sows) decreased with increasing age at the first mating. CLW sows mated at the age about 210 days achieved the highest number of parities and CL sows achieved the highest number of parities at the mating age 211-220 days. After the first parity, 32.31 % of CLW sows and 29.94 % of CL sows were replaced. The average number of piglets in the first litter (total born, live born and weaned) was higher in CL breed compared to CLW breed.