The current study aimed to determine and predict 12th-grade students' physics achievement in terms of some selected cognitive, physics-related effective, personal, and socioeconomic characteristics in Turkey. Four hundred and ninety-six students (273 female and 223 male) from 18 high schools formed the study group. Findings indicated that cognitive characteristics including science achievement and physics course grades explained the largest amount of variance (60.6%) in the achievement by itself. Physics interest and physics motivation as well as gender and perception of teacher-directed activities also explained a small amount of variance in student achievement. Although none of the socioeconomic characteristic variables were found to be significant, the entire model accounted for 64% of the variance in physics achievement.