The IPI, unlike the Minnesota Multiphasic Personality Inventory (another frequently used measure for police officer pre-employment evaluation), was developed specifically for the task of police officer selection; support for its validity in this context has been repeatedly demonstrated (Inwald, 1988, 1992). In the current test of the IPI's ability to predict police officer performance in the field, the initial sample consisted of 152 consecutive police officer applicants over a 16-month period. The subgroup of 14 women was removed from the sample because it was too small for independent analysis. Of the 138 consecutive male applicants, 1-year performance evaluations were available for 108. All of these applicants were initially seen for psychological screening following a conditional offer of employment. Study results provide support for the predictive validity of selected IPI scales regarding police officer performance in the field as evaluated by supervisors. One-year performance evaluations were associated with IPI Family Conflicts. High scores on this scale suggest conflicts with supervisors and peers. Other IPI scales that significantly predicted job performance were Guardedness, which measures the tendency to hide personal flaws; and Driving Violations, which predict a pattern of moving violations, fines, accidents, and/or disregard for the law regarding the operation of motor vehicles. The findings thus support the predictive validity of the IPI and identify specific characteristics of applicants that may influence performance in the field. 4 tables and 17 references