The impact of a mandatory Part 48 training program on the health and safety knowledge level of newly employed inexperienced miners in Texas was studied. Part 48 training was defined by compliance with Mine Safety and Health Administration's (MSHA) mandatory health and safety training requirements. A two-group pretest, posttest research design was utilized. Group one individuals were newly employed inexperienced persons who received mandatory Part 48 training in accordance with MSHA guidelines. Group two subjects were newly employed inexperienced persons who worked for companies that were exempt from conducting a Part 48 training program. MSHA's health and safety knowledge inventory was utilized. A significant difference was found in the health and safety training program when compared with individuals who did not receive the training . A significant difference was also found in the posttest scores for eight of the ten subject areas of the MSHA health and safety knowledge inventory for persons who completed a Part 48 training program when compared to persons who did not receive the training . Analysis of gain scores resulted in significant differences in the same subject areas indicated by posttest scores. It was concluded that MSHA Part 48 did have a significant impact on the health and safety knowledge level of newly employed inexperienced miners. Additional implications noted relate to the impact of a Part 48 training program on accidents, productivity, absenteeism, turnover, job satisfaction and management styles; role of MSHA in miner training; development of new training materials; methods of training; and the evaluation of health and safety training programs.