A study was carried out on a group of 505 preschool children. The children were given tests measuring their phonological discrimination, rhyme, initial phoneme detection and letter knowledge. In general, phonological discrimination and initial phoneme tasks are easier than the rhyme task. As children increased in age, phonological awareness and letter knowledge both increased. There are differences in phonological awareness between children according to their number of letter known. Letter knowledge is associated with all phonological measures and all variables of phonological awareness were good predictors of letter knowledge.