Purpose: Saudi Arabia is the main destination of religious tourism, as it has many spiritual places. With the passage of years, the figures for pilgrim visits are increasing, which is contributing to the economic growth of the Kingdom of Saudi Arabia (KSA). However, pilgrims’ visits can create strong opportunity costs in the form of environmental degradation. Owing to these notions, this study aims to discover the impact of religious tourism on the quality of the natural environment of Saudi Arabia. Design/methodology/approach: This study develops the empirical relationship between the variables by sampling the data from 35 years ranging from 1986 to 2020. The regression among variables was checked by using fully modified ordinary least square and dynamic ordinary least square models. Findings: This analysis proves that religious tourism has a direct impact on the environmental degradation of KSA. The unceasing visits of pilgrims accelerate various economic operations and activities, e.g. assimilation and digestion of industrial products, that necessarily hamper the environmental quality. In addition, this analysis indicates a negative impact on financial development, foreign investment and renewable energy consumption while the positive impact of fossil fuels assimilation and economic expansion on the secretion of CO2. The statistical findings are robust and verify the pollution halo hypothesis while rejecting the Environmental Kuznets Curve model in this region. Research limitations/implications: This analysis recommends restructuring the policies on hajj and Umrah visits. KSA Government should ensure green consumption by pilgrims. The limitation on pilgrims’ visits and the introduction of quotas are alternative policies to impede the pollution in this region. Originality/value: By controlling the routine determinants, this study offers innovative thoughts regarding the consequences of religious tourism on environmental quality.