Religious mass gatherings can foster contagious disease transmission in the home countries of pilgrims. Thailand has two major Muslim pilgrims: the Hajj and the Dawah. This study aimed to compare their knowledge (K), attitude (A), and self-reported practice (P), and qualitatively evaluate their perceptions regarding the prevention of respiratory infections. A cross-sectional mixed methods study was conducted. Multistage sampling was conducted in Hajj participants, while convenience sampling was used with the Dawah participants at two gathering ...