A database search uncovered 140 private sector drug testing cases disposed of by Federal and State courts over the 10-year period. Analysis of 99 State and 41 Federal cases indicated drug testing litigation accelerated rapidly in the late 1980's and then leveled off in the 1990's. Causes of employee action included wrongful discharge claims, tortious invasion of privacy, other tort claims such as negligence and infliction of emotional distress, and statutory violations. The percentage of cases won by employees was relatively high, and the statutory and common law of private sector drug testing gradually became more pervasive over time. Recognizing the nature and scope of the risk involved in employee drug testing, the author recommends that human resource managers exercise caution in drug testing policy design, implementation, and administration. An appendix lists Federal and State cases. 16 references, 12 notes, 2 tables, and 3 figures