Neurological complications can occur after heart transplantation and present with seizures. We examined the incidence of seizures from a population of adult patients who had received heart transplants over a period of 3 years. Brain MRI and clinical data were analysed to identify the risk factors for the seizures. Eight of the 166 post-transplant patients presented seizures (4.8%). The first seizures occurred with a mean of 30 days after the transplantation. For seven patients, the mean delay was 8 days, and for one, it was longer, 172 days. The analysis of brain MRI showed two main epileptogenic factors in the early post-transplant seizures: posterior reversible encephalopathy syndrome (PRES) due to cyclosporine treatment (n = 4) and cortical ischemic stroke (n = 5). In two patients, we identified multiple epileptogenic factors, including notably the association of PRES and cortical stroke. Since treatment of seizures in patients in the intensive care unit (ICU) after heart transplantation depends on identifying and correcting the causes, FLAIR and diffusion MRI sequences are needed, even if the patients have a previous history of epilepsy. Seizures were easy to control. In patients with PRES, imaging and clinical abnormalities improved when cyclosporine was replaced by another immunosuppressive treatment. Death of three patients was not related to seizures, but to infectious or malignant complications of immunosuppressive treatments (n = 2) or to post-stroke neurological deficit (n = 1). Mortality was similar among patients presenting seizures and those who did not.