In this review of dysmotility in cancer patients, we have focused on paraneoplastic GI dysmotility as it provides an excellent example of how derangements of the neuromuscular apparatus of the gut can affect GI motility. A high index of clinical suspicion, together with serologic evaluation using a panel of autoantibodies in selected patients, is important in ensuring the early diagnosis of paraneoplastic GI dysmotility and may help guide management. Although it remains unproved that paraneoplastic antibodies are pathogenic, they are useful diagnostic markers. A better understanding of the pathogenesis of these disorders, including the role of paraneoplastic antibodies, will, hopefully, lead to earlier diagnosis and improved adjunctive, immunology-based treatments. Furthermore, even though successful treatment of the underlying cancer may not lead to reversal of the GI dysmotility, the recognition of a paraneoplastic syndrome may lead to early cancer diagnosis and a better chance of successful treatment of the cancer and overall survival. Although rare, it is imperative that clinicians be aware of the association between malignancy and GI dysmotility so that they know when to investigate for an underlying malignancy.