This report describes an ischemic stroke after foam injection sclerotherapy of varicose veins in a patient with a patent foramen ovale. Foam injection sclerotherapy has created resurgence in the minimally invasive treatment of varicose veins. The United States Food and Drug Administration halted a clinical phase 2 trial of a commercial preparation of polidocanol microfoam in 2003 because of concerns relating to possible gas embolism. These trials were recommenced in July 2005. Neurologic complications such as transient visual disturbances and transient confusional states have previously been reported. This case, with its strong circumstantial evidence, illustrates the previously unconfirmed potential for embolic complications using this technique.