<strong><em>Introduction: </em></strong>At present most of the patients are educated, knowledgeable and actively participating in medical decision making. However, the literature on medical officers' knowledge, attitudes, and practices, as well as informed consent, in Sri Lanka is quite limited and our study is carried out to fulfil this gap. <em> </em> <strong><em>Methodology: </em></strong>A cross-sectional descriptive study was conducted among randomly selected 404 medical officers at two Teaching Hospitals in Sri Lanka. <em> </em> <strong><em>Results: </em></strong>Among the study group of total 404 medical officers, 57% (n=232) were males and 82% (n=331) were Grade Medical Officers. Ninety five percent (n=384) of them knew that informed consent should be obtained in vaginal examination and rectal examination and 98% (n=396) of them knew and apply the knowledge into practice in the case of children and other persons who are incapable of giving consent and 97% (n=392) of them knew that they have to consider the mental state of the patient before requesting consent. Almost all medical officers 96% (n=348) believe that the doctor who carries out the treatment or medical procedures is the best person to obtain informed consent from the patient. The majority of the medical officers 70% (n=283) only explain common risks. In comparison, 29% (n=117) explain all risks and only 01% (n=04) explain all risks including possible remote risks as well. <em> </em> <strong><em>Conclusion: </em></strong>A reasonable number of doctors have adequate knowledge regarding informed consent but are very poor in some areas. It is highly recommended continuous professional development program and knowledge updating program covering medical ethics at each hospital level.