The main goal in this paper is to describe how articles on clinical trials on atypical antipsychotic drugs in bipolar disorder reported their design. 25 controlled clinical trials were identified. Data were extracted on the general characteristics of the studies, including sources of funding, study design, and ethical issues. Most trials adequately report design issues such as patient selection, randomization, and flow of patients. However, only 8 of 25 studies reported pre-estimation of sample size; 22 articles claimed a double-blind design, but only 3 reported details on how blinding was performed; 17 trials failed to explicitly adhere to the Declaration of Helsinki.