Reality shock within organizations can be defined as the discrepancy between an individual's expectations established prior to joining an organization and the individual's perceptions after becoming a member of the organization. To investigate the effects of reality shock on organizational commitment, 109 bank tellers were monitored for 10 months after being hired. The subjects completed a modified version of the Job Descriptive Index (JDI) upon entering the teller program and again after 2 months, when they also completed the Organizational Commitment Questionnaire. After 2 months, branch managers evaluated the tellers' performance according to attendance, punctuality, number of customers served, and error rate. An analysis of the results showed that new employees definitely experienced reality shock as their initial expectations were lowered by work experience. The tellers' perceptions of the job and career facilitation were significantly reduced over the first 8 weeks in the organization. Reality shock significantly influenced tellers' commitment attitudes and desire to remain with the organization. However, reality shock had little or no effect on employees' quantity or quality of performance or on turnover. (BL)