Over a 16-month period, the Family Practice Residency at Madigan Army Medical Center coded 51,113 ambulatory problems using the International Classification of Health Problems in Primary Care (ICHPPC) coding scheme. The demography of this defined active duty, retired, and dependent population is described as well as the rank order of the major diagnostic categories and top 25 individual diagnoses. A plot of the major diagnostic categories seen by month over a 16-month period is presented. Comparisons between similar curves are made. Physician compliance to coding approached 75 percent and an average of 1.42 problems were dealt with (coded) per visit. Fifty percent of all patient problems recorded fell into 25 descriptive diagnoses. Ninety percent of all patient problems recorded fell into 163 descriptive diagnoses. These data compare favorably to the Virginia study. Comparison of the top 25 patient problems also revealed similarities between this and the Virginia study. Difficulties arise in comparing data because of the differences in coding schemes (RCGP vs ICHPPC). A universally adopted code for all family practice and ambulatory care research would help in overcoming this problem.