The technical colleges in Nigeria face challenges in assessing the psycho-productive skills of motor vehicle mechanic students due to a lack of standardized assessment tools. This study focused on the development and validation of psycho-productive multiple-choice skill tests (PMCST) for assessing the practical performances of technical college students in motor vehicle mechanic work across Ekiti and Ondo States. Adopting an instrumentation research design, instrumentation research design was considered appropriate because the study developed an instrument for assessment of practical skills of students. The study targeted a population of 350 National Technical Certificate (NTC) III students, encompassing three ability groups: 57 high, 201 average, and 92 low ability students. A draft copy of the PMCST, comprising 180 items, was generated and utilized as the instrument for assessment in five technical colleges across both states. Data analysis was performed using the split-half technique and Kudder-Richardson (K-R20), yielding a reliability coefficient of 0.84 for the test. Significant differences were found in the mean scores of the three ability groups. Among the recommendations arising from the study is the suggestion that examination bodies such as NABTEB, WAEC, and NECO integrate the PMCST into their certification processes for NTC students.