Learning physics at SMA, does not only involve memorizing facts, but it also engages the students in solving more problems without delay and attaining a real learning achievement. This study aimed to analyze the effect of project-based learning (PjBL) compared with direct instruction (DI) and student procrastination on student cognitive achievement in learning physics. This quasi-experimental study used a pretest-posttest non-equivalent control group design, involving 9 classes or 278 students of class X MIPA SMAN 1 Singaraja. The study sample consisted of 4 classes or 124 students. Data on student achievement and academic procrastination were obtained from the scores of a learning achievement test and an academic procrastination questionnaire. The data were analyzed descriptively and the two-way covariance analysis. The results of the study revealed that, first, there was a significant difference of academic achievement between students learned in the PjBL and DI models. Higher academic achievement was achieved by the students who learned with the PjBL model. Second, there was a significant difference of academic achievement between students who had high academic procrastination (HAP) and low academic procrastination (LAP). Higher learning achievement was achieved by students who had a LAP. Third, there was an interactive effect between the learning model and academic procrastination on the student academic achievement. Strong interaction occurred in low procrastination for both learning models.