This research aimed to: Firstly, identify social environment encouragement, social participation, patriotism knowledge, and patriotism behaviors of Indonesian and Malaysian youths Secondly, identify the contribution level of social environment, social participation, and patriotism knowledge to their patriotism behaviors Cluster random sampling was employed to determine respondents. A number of 1,172 respondents took part in the study, comprising 521 Indonesians and 651 Malaysians. This study employed descriptive statistics and multiple regression techniques in data analysis. Research findings show that Indonesian youths have better patriotism knowledge than their Malaysian counterparts. However, their patriotism behaviors both share the same level. Findings also show that social participation and patriotism knowledge variables are factors that significantly influence both Indonesian and Malaysian youths’ patriotism behaviors. Yet, the contribution levels of the factors differ in the two countries. The countries need to take more intensive efforts based on plans and programs to increase social participation and patriotism behaviors for their youths. Further research is also necessary to identify factors that dominantly contribute to youths’ patriotism, especially in Malaysia.

Index Terms- Social environment, social participation, patriotism knowledge, patriotism behavior, Indonesian and Malaysian youths