Perubahan kehidupan sosial masyarakat modern turut memengaruhi intensitas interaksi dan solidaritas sosial, termasuk pada masyarakat pesisir. Tujuan penelitian ini adalah untuk mendefinisikan praktik tradisi Nyadran, mengkaji bagaimana tradisi tersebut memperkuat persaudaraan Islam, serta mengidentifikasi nilai-nilai persaudaraan Islam yang diwujudkan di dalamnya. Penelitian ini menggunakan metodologi kualitatif dan melakukan penelitian lapangan di Tambak Lorok, Tanjung Mas, Kecamatan Semarang Utara, Kota Semarang. Model Miles dan Huberman digunakan untuk menganalisis data yang dikumpulkan melalui observasi, wawancara, dan dokumentasi. Berdasarkan temuan penelitian, tradisi Nyadran dipraktikkan melalui pertunjukan wayang, bancaan, salat berjamaah, persembahan ke laut, tahlilan, dan mauidzah hasanah. Tradisi ini berperan dalam mempererat ukhuwah Islamiyah melalui komunikasi, interaksi sosial, kerja sama, dan silaturahmi. Nilai yang paling dominan meliputi kebersamaan, kepedulian sosial, keharmonisan, dan silaturahmi. Changes in the social life of modern society have also influenced the intensity of social interaction and solidarity, including among coastal communities. The purpose of this study is to define the Nyadran tradition, examine how this tradition strengthens Islamic brotherhood, and identify the values of Islamic brotherhood embodied within it. This study employs a qualitative methodology and conducts field research in Tambak Lorok, Tanjung Mas, North Semarang District, Semarang City. The Miles and Huberman model is used to analyze data collected through observation, interviews, and documentation. Based on the research findings, the Nyadran tradition is practiced through wayang performances, recitation of prayers, congregational prayers, offerings to the sea, tahlilan, and mauidzah hasanah. This tradition plays a role in strengthening Islamic brotherhood (Ukhuwah Islamiyah) through communication, social interaction, cooperation, and social bonding. The most dominant values include togetherness, social concern, harmony, and social bonding.