Evidence from the research literature suggests that a variety of cognitive factors is responsible for chemistry achievement. This investigation examined the role of four cognitive factors, namely, formal reasoning ability, prior knowledge, field dependence/ independence, and memory capacity on achievement in chemistry as measured by tests of laboratory application, chemical calculations and content knowledge. The sample comprised grade 11 students from eleven high schools who were following the same chemistry syllabus. The results indicated that prior knowledge and formal reasoning ability were each statistically significantly related to variation in chemistry achievement. Field dependence/independence and memory capacity played no significant role in chemistry achievement.