This study investigates the effect of Problem-Based Learning (PBL) on students' Cash Book Performance skill among Senior Secondary 2 Schools Students in Port Harcourt Metropolis, Rivers State. One research question and one null hypothesis guided the study. The null hypothesis was tested at 0.05 level of significance. The design of the study was quasi-experimental design of pretest, posttest non-randomized control group. Population of the study was 2000 students. A sample of 99 students was purposively selected from two intact groups. Instrument for data collection was "Accounting cash book Performance Test" (ACBPT) validated by three experts with a reliability coefficient of 0.75. Mean was used to answer the research questions while analysis of covariance (ANCOVA) was used to test the null hypothesis. Findings revealed that students who were taught financial accounting using PBL performed better with higher post-test scores than those taught using Discussion method, but there was no significant difference in the mean performance scores of students in experimental and control group. This is because even though there was difference in the mean score of both group, the gap was not much to be considered statistical meaningful. The study concludes that problem-based learning method (PBL) enhances curriculum delivery and better equips students' with financial accounting skills and it was recommended amongst others that Teachers should ensure the use of PBL in teaching Financial Accounting for effective student's acquisition of Accounting skill.