We conducted a study of Mexican American women living in a US–Mexico border city who attended a gynecology clinic for Papanicolaou (Pap) smear. The objective of this study was to describe the cytologic outcomes of women who had atypical squamous cells of undetermined significance (ASCUS) diagnosis after a Pap smear and to observe any changes during follow-up colposcopy. A total of 852 abnormal Pap smear were identified through a computer search for a 6-month period. Histology data were available for 317 cases. Benign findings were observed in 45.4% of cervical biopsies. A clinically significant diagnosis was reported in the remaining tissue sample. The diagnosis report was either single or combined and recorded as follows: human papilloma virus 46.3%, cervical intraepithelial neoplasia (CIN) 1, 23.6%; CIN 2, 5.6%; and CIN 3, 1.5%. There was one case of invasive cervical cancer. Overall, the incidence rate of ASCUS was 5%. However, we found that a significant proportion of this population had CIN 1 through CIN 3. Furthermore, this population has traditionally been noncompliant and routinely failed to attend follow-up appointments. Based on these results, the clinician should not ignore an initial abnormal Pap smear. Therefore, it is not unreasonable to perform colposcopy in Mexican American patients with a first time diagnosis of ASCUS on routine Pap smear.