Objective: It is aimed to evaluate the prophylactic effect of flupenthixol decanoate in remitted BD patients. Methods: Remitted patients with bipolar disorder (BD), who had at least one mood episode each year in the last five years in spite of adequate pharmacotherapy, were included. Flupenthixol decanoate 20 mg/ml was administered in every two weeks. Hamilton Depression Rating Scale (HDRS), Young Mania Rating Scale (YMRS), Bipolar Disorder Functioning Questionnaire (BDFQ), General Assessment of Functionality (GAF) and Side Effect Rating Scale (UKU) were applied. Patients were followed up for 12 months. Results: Eight patients with a mean age of 34.7 +/- 7.5 were enrolled to the study. None of the patients were under monotherapy before the study enrollment. Three (37.5%) of the three patients were dropped out. The data of remaining 5 patients' were evaluated. At the end of the study mean number of mood episodes declined to 0.2 +/- 0.4 per year indicating a statistical significance and the mean score of BDFQ declined to 119.6 +/- 2.7. Conclusions: Flupenthixol decanoate significantly improved functionality and decreased the number of mood episodes allowing an alternative treatment even in remitted BD patients.