In this study, the genetic variation in populations of Scots pine (Pinus sylvestris L.), one of the species covering large areas in Turkey, was investigated. Open pollinated seeds were collected from I I populations in a natural distribution range. Six characters of seeds (length, width, ratio of length to width, weight/1000 seeds) and seedling (cotyledon number and hypocotyls height) and two enzyme systems (leucine aminopeptidase, LAP; glutamate oxaloacetate transaminase, GOT) were investigated. Significant differences were detected among the populations for the morphological characters. In addition, isozyme patterns of the two enzyme systems revealed that Lap has two loci (one with 2 alleles and the other with 3), while Got has three loci (two with 3 alleles and the third one with 2 alleles). Polymorphic loci were 80% on the average. The mean number of alleles per locus was 2.02, and expected heterozygosity was 22%. The mean total genetic diversity was calculated as 0.235; the mean gene diversity within populations was determined as 0.220, and the average between-subpopulation diversity was 0.014. Averaged genetic distance was 0.081. According to the genetic distance, population number 2 was separated from the remaining populations.