Inflammatory bowel disease (IBD) patients are at an increased risk of developing colorectal cancer (CRC), which is thought to develop via the adenoma-carcinoma pathway. Since the discovery of the serrated carcinogenesis pathway and serrated polyposis syndrome (SPS), the incidence of carcinomas arising from serrated lesions in IBD patients has increased. We report three cases of long-standing IBD patients with associated serrated polyposis syndrome. At present, the pathophysiology of serrated lesions in IBD patients is not fully understood and there is a lack of strong evidence to confirm whether the manifestation of both conditions represents an increased risk of developing cancer. Therefore, more accurate surveillance guidelines are needed and are being actively investigated at present.