The authors studied the age composition in two samples (Edirne: 17 m a.s.l. and Bolu: 1,250 m a.s.l.) of Lacerta trilineata BEDRIAGA, 1886, in Turkey. Aging by skeletochronology showed that the maximum age of the lizards was about seven years in the Bolu and five in the Edirne sample. The adult survival rate was 0.59 % in males and 0.24 % in females of Bolu. The adult life expectancy was calculated as 2.94 years for males and 1.82 for females in the Bolu sample. Age at sexual maturity was two years in both samples. Although the mean age of the high altitude sample was older than of the low altitude sample, the mean snout-vent-length of the latter was longer.