The FDA decisions to approve the use of dabigatran, rivaroxaban, apixaban and edoxaban for atrial fibrillation were based on pivotal clinical trials that were performed with numerous irregularities including the deliberate omission and fabrication of data. By approving the use of these drugs, regulatory agencies showed a worrying lack of rigor, since they ignored the serious deficiencies detected by their own inspectors in pivotal trials. No reliable information is available on the harm/benefit ratio of dabigatran, rivaroxaban, apixaban and edoxaban for atrial fibrillation vs. warfarin. Regulatory agencies should make complete data from trials publicly available, to ensure transparency and provide reliable information. This would allow for the optimization of treatments.