Aim: Atypical squamous cells of undetermined significance (ASCUS) are a cervical cytologic finding category suggestive but not definitive of squamous intraepithelial lesions. ASCUS remains an incompletely described entity and accounts for even 5%-10% of reported Papanicolaou (Pap) smears. The management of women with such cytologic findings remains controversial. The aim of this study was to evaluate the cytology laboratory findings with regards to ASCUS diagnosis, using cervical Pap smears, and colposcopic biopsies, as well as their management. Materials and Methods: This is a retrospective study of patients with ASCUS Pap smears taken during the period January 2010 – December 2010 in the Second Department of Obstetrics and Gynecology, Aretaieion Hospital. Results: During the study period, 657 Pap smears were examined at the Aretaieion Hospital; moreover, seven patients, whose Pap smears were cytologically diagnosed with ASCUS, were referred from other clinics, providing a total of 42 cases with a descriptive diagnosis of ASCUS for review. Of the 42 cases, eight were not studied because they were either lost in follow-up or they did not have available data. The remaining 34/42 patients were evaluated by colposcopic examination and directed biopsies where necessary. The ratio of ASCUS to low-grade squamous intraepithelial lesion (LGSIL), high-grade squamous cell intraepithelial lesion (HGSIL) or squamous cell carcinoma (SCC) was 5/34, 1/34, and 0/34, respectively. In the 34 ASCUS cases evaluated by colposcopy, the age distribution varied from 22 to 54 years. Eight of 34 cases did not have a child, 7/34 were primigravida, 18/34 were secondigravida, and 1/34 had four children. Four out of 34 cases were postmenopausal, 3/34 referred no history of abnormal bleeding, 21/34 were smokers, 6/34 used oral contraceptives, 2/34 used intrauterine devices, 1/34 took replacement of hormones, 4/34 had prior abnormal Pap smears human papillomavirus (HPV), or 1/34 had previous cancer (breast cancer). Colposcopy was inconclusive in 4/34 patients, while 8/34 cases were negative for Schiller and acetic acid tests and also had normal colposcopy. Infectious organisms were found in 8/34 patients with ASCUS, including actinomyces (1/8), trichomonas (5/8), and candida albicans (2/8). Histologic tests revealed 16/34 koilocytosis cases, 5/34 LGSIL, 1/34 HGSIL, and 0/34 SCC. Conclusion: The dilemma in the management of patients with an ASCUS diagnosis still exists as a significant problem for clinicians.