The current study explored the effects of two teaching styles, authoritative and authoritarian, on students' mathematics motivation. The two motivational constructs examined were intrinsic and extrinsic motivation. Data were collected from 425 Omani 8th grade students (males = 202/females = 223, mean age = 13.44, SD = 0.79). Through two questionnaires, students reported their perceptions of their math teachers' teaching styles, and their own motivational orientation towards mathematics. Multiple regression models were used to analyze the data. The findings suggest the two teaching styles play a role in predicting students' mathematics motivation. An authoritative teaching style seems to be the better predictor of the two motivational constructs, when compared with an authoritarian style. Eighteen percent of the variance was accounted for in the intrinsic motivation model, compared with only five percent in the extrinsic motivation model. The educational and cultural contexts were discussed in relation to the research results.