Performance testing provides an important complement to urine testing as a determinant of fitness for duty. Performance testing can be conducted immediately to screen out impaired workers before they undertake safety related job functions. Urine testing involves the expense and delay of laboratory testing, and results relate more to life style than current on-the-job performance capability. This paper reviews performance based testing and discusses the development and application of two performance based screening devices. One device has the capability of rapidly screening for impaired psychomotor performance given previous baseline data. The second device provides the potential for screening psychomotor and divided attention performance without prior experience or baseline data.