Objective: To study the pattern of psychotropic prescription among Thai bipolar outpatients by using cross sectional study. Methods: This is a cross-section study of bipolar outpatients treated in 4 general and psychiatric hospitals during January to March 2005. Results: Two hundred eighty-four outpatients with the age of 15 year olds or more were enrolled. The psychotropic prescribing pattern in Thai bipolar patients is similar to those found in US and UK studies. Valproate was the most frequently prescribed medication followed closely by lithium. Aypical antipsychotics were the third. The only exceptions are the smaller number of antidepressant uses and the more frequent use of typical antipsychotics in Thai patients. Conclusions: The study shows the similar psychotropic prescribing pattern given to Thai bipolar outpatients as compare to those in US and UK. The major differences are that Thai clinicians prescribed more typical antipsychotics and less antidepressants.