This study explores the prevalence of developing Axis I disorders at various time points within an obsessive-compulsive disorder (OCD) population. A sample of 409 patients diagnosed as OCD according to the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders (American Psychiatric Association, 1994) participated. Of the 409 patients, 132 (32.2%) developed at least one other Axis I disorder. Odds ratio data indicates that an anxiety disorder, mood disorder, eating disorder, or tic disorder is likely to occur first. Second disorder is likely to be another anxiety disorder, mood disorder, eating disorder, somatoform disorder (tic disorders fall out of the continuum). The third disorder is likely to be a mood disorder, or anxiety disorder (all other disorders fall out of the continuum). Demographic data including gender, religion, occupation, marital status, and family psychiatric history is similar to the data reported in other studies of primary OCD. It is suggested that although OCD may present with additional comorbid conditions, other distinct pathology may emerge (be inserted) independently over time. This supports the conceptualization of OCD as a continuum, where additional diagnoses may be expected to occur in the time course of the condition.