A unique phenomenon in Bangladeshi cultural heritage is the tendency to wear traditional costumes at the festivals. This research examines the influence of wearing traditional Bangladeshi costumes for the festival observance. Based on the theoretical background of Bangladeshi festival heritage, five factors were derived: togetherness, tolerance, simplicity, aestheticism, and cultural revival. This research empirically analyzed 310 participant’s data who attended UNESCO (United Nations Economic and Social Council)–recognized world intangible cultural heritage festival, “Pohela Boishakh” (first day of Bengali New Year) held in Bangladesh. Exploratory factor analysis showed that all five factors are statically significant for the impact of heritage festivals. Multiple regression analysis revealed four factors out of five statistically significant for festival importance, and all factors are significant for the tendency of wearing traditional costumes at the heritage festival.