The purpose of this study was to determine the most influential people in the career choices of medical laboratory science students. Methods of investigation used by these students were also explored. A questionnaire survey indicated that students were influenced more by professionals in the field, and that high-school guidance counselors were unable to furnish current and accurate information for decision making. Results of the study have implications for improvements in all areas of guidance. Based on the findings, the best interests of the students are served when both guidance counselors and professionals in the medical laboratory science field provide students with understanding, encouragement, and factual information.