The Faculty of Electrical Engineering, University Technology Malaysia is currently moving towards a Problem-Based Laboratory implementation rather than the conventional instructional-based laboratory for final year students. The laboratory has commenced session with about 500 students' registration in the 2007/08/1. The Problem-Based Laboratory requires each group of four or five students to solve three given problems in three different laboratories per semester. Each problem has to be solved by conducting the related experiment within four weeks. As they are various evaluation criteria that need to be considered, a web-based evaluation system is proposed in determining the final grade of the students. The evaluation system allows the laboratory coordinators to log in as administrators in order to monitor the evaluation process, which involves both the laboratory technicians and students. The developed web-based evaluation system has proven its capability in working interactively with the users. From the uploading of student's information, group division, marks insertion and total marks calculation for the final grade. It is anticipated that the web-based evaluation system can ensure reliability and security in determining a student's grade in a Problem-Based Laboratory in a shorter time especially when dealing with a large number of students. (Contains 8 figures and 1 table.)