The purpose of this study is to discuss the forms, the factors and the implications of adaptation of Muhammadiyah members to the religious tradition of Nahdlatul Ulama. Robert K. Merton's theory was used to see the adaptation process which has been carried out by Muhammadiyah members in Gorontalo. The study applied a phenomenological qualitative approach. In the process of collecting data, the study used observation and interview techniques. The data analysis classified the data including primary and secondary data. The results showed that the adaptation of Muhammadiyah members was in the form of implementing the religious tradition of Nahdlatul Ulama. They were: mongaruwa (spirit prayer), molibungo (female circumcision), and be'ati (oath of allegiance). The factors that caused the adaptation of Muhammadiyah members were the process of collaboration, and continuously mutual openness with Nahdlatul Ulama members in the community. In addition, the implications of the adaptation: first, there was a harmonious social life among Muslims. Lastly, Muhammadiyah members were not rigid in the midst of the religious traditions of the Nahdlatul Ulama members and the local traditions of Gorontalo.