A report of ASCUS is always confusing or painful to the clinician, as histological correlate of this diagnosis is wide, ranging from a totally normal cervix mucosa to infiltrating carcinoma; most of the time it is the result of benign inflammatory or reactive changes. This is the reason why this category has evolved since its introduction in the Bethesda system for reporting cervical cytology in 1988, to achieve a closer link to the lesional diagnosis. The most recent modification took place in 2001, to subcategorize the ASC into ASC-US and ASC-H. The present review provides guidelines to manage these diagnoses.