We examined the effects of religiosity and the practices of religions among the Buddhists and Muslims aged 20 to 79 in Thailand on maintaining positive attitudes toward older people. Factor and multiple regression analyses are applied, using data from the 2011 National Survey on Conditions of Society and Culture. The measures of perception of older people are Social Value and Personal Value. Religiosity is measured by the self-assessment of religious strictness and one’s own practices according to the religious principles. Among Buddhists, the practices are measured by the frequency of praying, Takbat, Pancha Sila, and meditation. For Muslims, the practices are measured by the frequency of doing Salat, observing Saum, and giving Zakat. We found that religiosity and some practices of religions have positive effects on the perception of the value of older people. In addition, social policy for a smooth transition to an aging society should be considered alongside this religious mechanism.