Introduction: Basic sciences are an important part of education in medical courses, which without it training the competent and efficient physicians is impossible. Given the complexities of teaching and in particular the teaching of basic sciences and its influence of various factors, comprehensive investigate this phenomenon was felt. This study was aimed to explore the underlying factors affecting the teaching based on experiences of successful faculty members of basic sciences in Isfahan medical school. Methods: This qualitative study was conducted using conventional content analysis. The data was collected using purposive sampling and semi-structured interviews with faculty members of basic sciences and group interviews with the students of basic sciences. Results: After analysis the data, the extracted data were divided into three main categories and seven sub- classes, including strengthen the construction of teaching infrastructures (lesson plans, useful and practical educational materials, and continuous curriculum reform), improving the teaching process (facilitating learning and appropriate transfering of content) and completing the teaching process (appropriate evaluation tool and continuity assessment). Conclusion: Some positive experiences, such as reducing volume of materials, teaching useful and practical materials, attractive teaching, early clinical exsposure and provide the appropriate educational materials should be considered as a model and to eliminate negative experiences such as teaching of pure basic sciences, drowning in detail, the emphass on memorization, indulge in speech, the multiple choice tests systems and some faculty members were not ready for some of teaching methods should be taken account some items.