Small cell lung cancer (SCLC) is often associated with paraneoplastic neurological syndromes like intestinal pseudo-obstruction. This syndrome is characterized by dysmotility of the bowel without mechanical obstruction. The pathogenesis of the syndrome is thought to involve autoimmune mechanisms with production of antineuronal antibodies and enteric neuronal degeneration. We report a patient with severe constipation as a clinical presentation of a paraneoplastic intestinal pseudo-obstruction complicating SCLC, who was successfully treated with the somatostatin analogue octreotide. This may be explained by effects of hormone-like substances from the tumor directly inhibiting the gut motility, rather than by autoimmune mechanisms.