Abstract In this study an attempt was made to compare and find the relationship between students’ achievement in theoretical and practical aspects of Mock Senior School Certificate Examinations in Chemistry. The study adopted a correlational research design which specifically, compared recorded scores of students in theoretical and practical aspects of chemistry MOCK Examination of 2007-2009 academic sessions. Five research questions and five hypotheses guided the study. A total of 1200 SS3 students drawn from twelve secondary schools within Potiskum education zone of Yobe state were used. The students were drawn through purposive sampling technique. Eight male schools and four female schools were used for the study. Mean and standard deviation of scores were used to answer the five research questions while Pearson Product-Moment Correlation analysis was used to test the five null hypotheses at p< 0.05. The result showed that students achieved better in the theoretical aspect than in the practical in the MOCK Examination in Chemistry 2007 – 2009 in Potiskum Education Zone of Yobe State. It also indicated that Gender and Location had differential effects on achievement of students in Chemistry Examination. The male students achieved more significantly better than their female counterparts in both theoretical and practical aspects. The study revealed that students in the urban area achieved more significantly better than their counterparts in the rural area in both theoretical and practical aspects. It also revealed that there were no significant relationships between students’ achievement in the theoretical and the practical aspects of the examination. Thus it was concluded that students do not have enough laboratory experience to cope with the demand of the external practical examination in Chemistry. Therefore it was recommended that Chemistry teachers should give more priority to practical experiments as part of instruction in order to improve students’ understanding of practically related concepts. Theoretical and practical instructions should be given side by side.
