A study was conducted to evaluate the effectiveness of self instructional module on knowledge of automobile mechanics regarding occupational safety at selected workshops in Hubballi. Totally 50 automobile mechanics were selected by non probability purposive sampling technique. The Knowledge was assessed by using structured knowledge questionnaire. The study results reveal that during pre test, 38(76%) mechanics had inadequate knowledge, 12 (24%) had moderate knowledge regarding occupational safety. After introduction of Self Instructional Module all automobile mechanics (100%) had adequate knowledge. The paired‘t’ test value revealed that the gain in the knowledge is statistically significant at 5% level. The ÷2 value revealed that the gain in knowledge and socio demographic variables is independent. The study findings concluded that Self Instructional Module on occupational safety is effective in improving knowledge of automobile mechanics.