Background: Keeping up-to-date with current best evidence for the care of patients is challenging. It is recommended to take a "4S" approach to evidence-based information access, that means starting with systems and proceeding to synopses, syntheses and studies if failing to retrieve evidence-based answers within systems. The present state of evolution of systems is bedside sources of evidence-based information. To choose the appropriate databases regarding the limited financial resources particularly in developing countries is a concern for medical libraries. Objectives: To compare proportion of questions that can be successfully answered and also the time of reaching the correct answer using four bedside sources of evidence-based information. Methods: This study was a parallel randomized (double blind) controlled trial. Ninety-six first-year specialist registrars (residents) in different specialties were randomly allocated to four parallel groups using: 1) ACP PIER, 2) Essential Evidence Plus (formerly InfoRetriever), 3) First Consult and 4) UpToDate. A total number of 24 clinical scenarios followed by formulated questions were randomly allocated among participants in each group; each participant received three scenarios including diagnosis, prognosis and therapy and was asked for retrieving answers within allocated database. Retrieved answers and time-to-answers were recorded by special designed software. The researchers team determined if each recorded answer addresses the question appropriately. Results: Seventy-five per cent of questions were answered in UpToDate, 55% in First Consult, 39% in Essential Evidence Plus and 41% in ACP PIER (P < 0.001). Diagnosis questions were answered 70% by UpToDate, 56% by First Consult, 41% by ACP PIER and 36% by Essential Evidence Plus (P=0.101). For questions of prognosis, the answers found 65%, 43%, 27%, 27% by UpToDate, First Consult, ACP PIER and Essential Evidence Plus, respectively (P=0.029). Therapy questions were answered 91% by UpToDate, 65% by First Consult, 54% by ACP PIER and 54% by Essential Evidence Plus (P=0.027). None of these databases stands superior regarding time-to-answers (P=0.182). Conclusions: Users reported that they found the answers to more questions with UpToDate than the other resources evaluated. However, the time of reaching the correct answers does not obviously differ among evaluated bedside information sources.