Anorectal malformations (ARM) include a wide spectrum of congenital defects of the anus, anal canal and rectum, which are often associated with congenital anomalies of other organ systems. They appear with different clinical presentations ranging from simple imperforate anal membrane to very complex defects. They are usually detected immediately after birth or early at neonatal age, but some patients with the milder defects are diagnosed at a later age. Objectives: The aim of this study is to analyze the incidence of patients with ARM diagnosed after neonatal period, clinical features and consequences of delayed diagnosis. Materials and Methods: Since 2010 we performed a combined retrospective and prospective analysis of a total of 76 patients with anorectal malformations, diagnosed and treated at our clinic between 2005 and 2014. We analyzed patients’ age at the time of diagnosis, sex, type of defect, associated anomalies and postoperative functional outcome. Results: 18 patients with ARM (23.68%) were diagnosed beyond the neonatal period. Of them 11 were female (61.11%) and 7 male patients (38.89%). The earliest diagnosed patient was a male of three months of age, while the latest diagnosed patient was a female of 8.5 years of age. All patients had low type anomalies, presented with anal stenosis (16), perineal fistula (1) and vestibular fistula (1). Six patients (33.33%) were also diagnosed with associated anomalies. Conclusion: High incidence of delayed diagnosis of ARM highlights the importance of a careful, comprehensive clinical examination of the perineum of newborns. All patients with severe and chronic constipation must be evaluated for eventually missed diagnosis of low type anorectal malformations.