Science laboratory activities are often known for their potential role in helping students to construct meaningful knowledge. The use of laboratories for making experiments and observations by traditional methods instead of using them as a real learning environment through researches, problem solving and thinking, hinders the exact construction of students' knowledge and meaningful learning. This situation has made the use of active teaching strategies compulsory in science laboratories. The purpose this study was to investigate the effect of V-diagrams on the achievement of students in biology laboratories. Obtained data were analyzed by t-test and results revealed statistically significant differences between the means of achievement scores of experimental and traditional groups in favour of experimantal group using V-diagram.