Background: The use of medical software applications has changed the clinical practice over the last decade. The usage of smart phone among the population is growing rapidly, including healthcare professionals, but the extent of the increase in their knowledge and practice due to the enhanced usage of smart phone is not known. This study aims at determining the knowledge, attitude and preferences of physicians regarding the use of Medical Apps in their professional practice. Methods: A cross sectional study was conducted in the governmental primary health care centres in Jeddah, Saudi Arabia, using a sample size of 178, selected through randomized cluster sampling. Self-administered questionnaires were used for collecting the data. Results: The study revealed that 92% of the responders were aware of the availability of Medical Apps and most of the doctors had a positive attitude towards the use of Medical Apps. The most prominent use of Medical Apps was to get additional medical information to update their knowledge. The majority of responders had already installed them on their smart phones and most of them used the Apps at least once in a day. Medscape was the most common medical app used by the study population. Conclusion: The findings of the study show the existence of good knowledge and a positive attitude towards the use of Medical Apps among the doctors. Most frequently used applications were free Medical Apps.