Physicians have to deal with a broad range of medical problems in clinical practice, thus making the timely acquisition of relevant information is a critical skill for physicians to improve care quality. The current national study investigates how physicians search for medical information and analyses how they use online medical databases. A structured questionnaire survey was conducted, with 457 valid returns collected. Internet-based resources (Web portals, online databases, and electronic journals) were more often accessed by physicians to look for medical information than personal or paper ones. Almost universally, physicians have accessed online databases. MEDLINE was the most frequently accessed database. Furthermore, physicians under 50 years old tended to access online databases more often than their elder colleagues (OR = 5.27, 95% CI = 1.96-14.14 for age <35; OR = 4.68, 95% CI = 2.07-10.60 for ages 35-50). In addition, physicians with faculty position were more often accessing online databases (OR = 3.32; 95% CI = 1.75-6.30). Other factors - including clinical experience, administrative position, gender, academic degree, and professional specialty - carried no significant differences. These data may assist in determining how to promote the use of online evidence-based medical information for clinical services.