In the spirit of maintaining health and looking for drugs to cure a disease, the question of halal and haram still needs to be answered. Finding and choosing halal medicine is a must for all Muslims. Staying away from what is haram is also our responsibility. This coincides with the words of the Prophet Muhammad SAW "Seeking halal is obligatory for every Muslim" the hadith narrated by ibn Qadamah. To determine the influence of religiosity, knowledge, perception, and attitude of Muslim doctors on intentions that affect behavior change from using conventional pharmacy to halal pharmacy. herbs in Indonesia. Methods: Using an online survey that was distributed to all Muslim doctors in Indonesia. Result: From 435 respondents we find that religiosity has a significant effect on attitudes, perceptions and intentions so that they are able to change the behavior of Muslim doctors from using conventional pharmacy to halal herbal pharmacy. Knowledge alone will not be able to change the behavior of Muslim doctors in the context of this study. It is necessary to increase religiosity that can encourage a Muslim doctor to change the habit of using conventional pharmacy to hallal herb.