Background: Individuals pursue teaching careers for numerous reasons, such as for instrumental or prosocial purposes. Aims: This study examined the personal (instrumental motivation) and social (prosocial motivation) utility of teaching as predictors of teaching quality in terms of clarity of instruction, classroom management, and cognitive activation. Sample: We used data from the Teaching and Learning International Survey (TALIS) 2018, which included 50,595 teachers from 1252 schools in 10 countries and regions. Methods: We performed a series of regression analyses to test a model of instrumental and prosocial motivation to predict three indicators of teaching quality (clarity of instruction, classroom management, and cognitive activation) while controlling for demographic characteristics (age, sex, educational level, and teaching experience). We examined this model in countries and regions from Eastern (Japan, Korea, Singapore, Shanghai and Taipei) and Western (Australia, Canada, New Zealand, United Kingdom and the United States of America) cultures. Results: Results demonstrated that instrumental motivation predicted clarity of instruction in the East and classroom management in both the East and West; prosocial motivation, however, was a more consistent predictor of all indicators of teaching quality, except classroom management in the West, across cultures. Conclusion: Teachers' prosocial motivation to benefit others and contribute to society must be considered to understand teaching quality across various cultural contexts. Implications for theory, practice and policy are discussed.