This is a comparative study of achievement scores of students in economics after three objective test formats. Two research questions and three hypotheses guided the study. A 2x3 mixed ANOVA design was used to carry out the study. The sample for the study comprised of 533 Senior Secondary II (SSII) students offering Economics drawn using multi-stage sampling procedure from public secondary schools in Anambra State. Economics Achievement Test in short-answer, true-false and multiple-choice formats were utilized in data collection. The reliability indices of the instruments were 0.76, 0.78 and 0.83 respectively for short-answer, multiple-choice and true-false item formats. Kuder-Richardson Formular 21 was employed to measure the internal consistency reliability of the test scores for the three objective tests. Each student took the three objective tests. The collected data were analyzed using mean, standard deviation and two-way ANOVA. The findings of the study showed that students performed better with multiple-choice format relative to other objective test formats. While the tested hypotheses revealed that a significant difference existed between the achievement scores of male and female SSII students exposed to short-answer test and multiple-choice formats, no significant difference existed between achievement scores of male and female SSII students exposed to true/false test format in economics. It was further revealed that there was no interaction effect between objective test formats and gender of secondary school students studying economics. It was recommended that examination bodies should keep relying on multiple-choice since it leads to higher achievement scores than others.