The study of pro-environmental behaviour and its determinants is poignantly important given the current trends of environmental and climate change. We aimed to investigate the role of motivation in explaining pro-environmental behavior in Russia. In addition, the explanatory role of motivation was considered in relation to two other important predictors of pro-environmental behavior: environmental concern and connectedness to nature. The study had a cross-sectional design and involved 462 respondents (56.7% women; M_age = 36.73, SD = 11.77; 56.5% higher education; 60% residents of large cities). Multiple regression analysis and dominance analysis were used. Among the self-determined forms of motivation, internal and integrated motivation positively explained pro-environmental behavior, with integrated motivation explaining all behaviour types. Identified motivation did not significantly explain behavior. Among the non-self-determined forms, introjected motivation positively predicted behavior, extrinsic motivation showed mixed results, and amotivation was a negative predictor. Gender, age, and city size predicted behavior positively, while education and income predicted it negatively. In addition, integrated motivation was the dominant predictor for waste management behaviour, social behaviour and resource conservation behaviour. Age, income, and education were marginally dominant, compared to integrated motivation, predictors of sustainable purchases and climate-relevant behaviour (aiming to reduce carbon footprint). While being important predictors, intrinsic motivation, amotivation, environmental (biospheric) concern, and connectedness to nature, were less dominant compared to integrated motivation for all behaviour types.