This quantitative-qualitative study seeks to determine the effectiveness of TIMS (Thomasian Interactive Multimedia Software) in teaching the introductory topics in Trigonometry. The acceptability of the software to the student respondents was established using the content, design, interface, and effectiveness of the media used as the evaluation criteria. The critical trial use of the software involving a small group of students was employed to elicit the needed information. It aims to provide meaningful report which includes the strengths and weaknesses of the software, the recurring problems, and constraints during its implementation, and a critique of the software as to how it should be improved for future use.