Mental health has become one of the most pressing global concerns, yet modern psychology tends to approach it mainly through biological and cognitive lenses while giving limited room to the spiritual dimension of human beings. Islam offers a holistic view in which the tranquillity of the heart is inseparable from the remembrance of God, as expressed in QS. Ar-Ra'd : 28. This study examines the concept of mental health formulated by the ninth-century physician Abu Zayd al-Balkhi in Masalih al-Abdan wa al-Anfus and reads it through the lens of maqashidi interpretation of QS. Ar-Ra'd : 28. Using a qualitative library-research method with a descriptive-analytical design, data were drawn from the Qur'an, classical exegetical works, al-Balkhi's treatise, and contemporary scholarship, then analyzed through reduction, presentation, and interpretive analysis. This study aims to analyze the concept of mental health from an Islamic perspective, examine Abu Zayd al-Balkhi's concept of mental health in Masalih al-Abdan wa al-Anfus, and analyze QS. Ar-Ra'd: 28 from the perspective of maqashidi interpretation and integrate it with al-Balkhi's concept of mental health. The findings show that al-Balkhi classified psychological disturbance into four categories-fear and panic, anger, sadness and grief, and obsessive thought-all of which can be addressed through a combination of cognitive and spiritual strategies. Read maqashidically, QS. Ar-Ra'd : 28 positions the remembrance of God (dzikrullah) as the wasilah that produces tranquillity of the heart (tuma'ninah al-qalb), pointing toward the higher objectives of preserving the soul (hifz al-nafs) and preserving the intellect (hifz al-'aql). The study concludes that al-Balkhi's psychological framework and the Qur'anic teaching on dzikr converge in offering an integrative, spiritually grounded model of mental health.