Study purpose: We ascertained the follow-up care after an abnormal cytology (Papanicolaou) screening in the San Martín region of Perú and assessed the status of women who had not received adequate care. Basic procedures: We identified women with an abnormal cytology and assessed their medical records, laboratory registries, death certificates and interviewed them at home. Re-screening, diagnosis and treatment were offered. Main findings: Only 46 (25%) of the 183 women identified received appropriate follow-up care. At re-screening 31 (34%) had a normal result, 9 (10%) were diagnosed with CIN1 and 50 (56%) had CIN2 or worse. Principal conclusions: In this setting, follow-up care after an abnormal cytology was very poor and could explain the lack of impact of cervical cancer screening. Women with an abnormal cytology constitute a high-risk group that should be a priority for health services.