The study aimed to develop and validate a teacher’s laboratory competence evaluation instrument (TLCEI) as an assessment tool for rating the competencies of laboratory teachers. This research was particularly conducted to identify the domains of competencies of teacher in handling laboratory classes and to determine the instrument’s validity and reliability. Cross-sectional design was employed using descriptive and analytic approaches to data analyses. A 54–item try-out version of the instrument was created based on the indicators identified by the selected laboratory instructors during interviews. One thousand college students with laboratory subjects participated in the pilot test. Item analysis of the try-out instrument reduced the 54 items to 35 for the final version. Pilot–testing for the reliability of the final version involved 100 students. The principal component exploratory factor analysis (EFA) indicated that the instrument measures three constructs such as “Laboratory Instruction,” “The Laboratory Environment,” and “Planning and Preparation.” The three–factor solution explained a total of 68.78% variance in the scale responses. The reliability coefficients supported that the TLCEI is highly consistent in measuring the constructs defined by the scale.