The authors present the results of a review of 53 pathology malpractice claims and incident reports. The review was conducted by The Doctors Company in 1989 and 1992. Many of the claims fell into broad diagnostic categories that suggested common underlying problems. These categories include malignant lymphoma, malignant melanoma, breast fine-needle aspiration, cervical Papanicolaou (Pap) smears, prostate needle biopsies, and errors by expert consultants. Sixteen cases are presented, chosen to illustrate some of the errors in judgment and communication that can result in a malpractice claim. Specific recommendations will be made to address repetitive problems of pathology practice as uncovered by this review. Some of these problems suggest topics for continuing medical education programs as well as subjects that need further emphasis in residency training. Since 1989, the claims frequency for pathology (number of claims per 100 insured physicians per year) has increased from 8.8 to 10%, whereas for all physicians the claims frequency has decreased from 18 to 17.2%. This review is an attempt to identify some of the causes responsible for this increase and to suggest both diagnostic and quality assurance strategies for dealing with them.