Between Dec. 1992 and July 1993, 13 greenhouse operations took part in on-site training programs concerning pesticide application safety. Each program involved a pre-quiz, post-quiz, presentation of two videotapes, discussion, session evaluation, and follow-up evaluation 1 month after each session. A total of 253 Colorado greenhouse employees participated in the programs, which fulfilled the employee training requirements for the Occupational Safety and Health Administration's Hazard Communication standard concerning hazardous materials in the workplace. Quiz scores increased from the pre- to the post-program quiz, from 17.3 to 22.1 points out of a possible 27. Post-program evaluations indicated that the vast majority of respondents either “agreed” or “strongly agreed” that (percentages in parentheses): “the training program will be helpful” (85%), “I understand hazardous materials better” (81%), “the training videos helped understanding” (84%), and “I would like the training done regularly” (79%). Follow-up evaluations showed that most “agreed” or “strongly agreed” that (percentages in parentheses): “I have used at least one new safe handling practice” since the program (55%), and “I plan to use more” safe handling practices (82%). This method of instructing employees about hazardous materials would be applicable to others interested in safety issues.