The Inquiry-Based Microscale Experimentation Approach was used in this study. To investigate the effect of this approach on students’ performance two research questions and two hypotheses were formulated to guide the study. A pre-test, post-test non-randomized quasi-experimental design was used. The population for the study was one thousand seven hundred and fifty-six (1,756) senior secondary II Chemistry students (2017/2018) academic session. Purposive sampling technique was used to draw a sample size of one hundred and twelve (112) students. Two research instruments namely Redox Reaction Concept Performance Test (RRCPT) and Electrolysis Concept Performance Test (ECPT) were developed for data collection. The RRCPT consisted of twenty (20) multiple choice objective test items while ECPT comprised of forty (40) items. The reliability coefficient of 0.75 and 0.82 was obtained using Kuder Richardson 20 (K₂₀) for the Redox Reaction Concept Performance Test (RRCPT) and Electrolysis Concept Performance Test (ECPT) respectively. Data collected were analyzed using mean, standard deviation and Analysis of Covariance (ANCOVA). The findings of the study established that inquiry-based microscale experimentation approach has a significant and positive effect on students’ performance. The findings also revealed that there is no significant difference in the performance of male and female students taught the concept of electrolysis using the inquiry-based microscale experimentation approach. Thus, gender is not a major factor in students’ performance. The study, therefore, recommended that Chemistry teachers should incorporate this approach into the teaching-learning process of electrolysis in order to create a unique, interesting and motivating learning environment.