This paper examines existing literature on green consumerism and discusses various influences on green purchase behaviour. The study digs into less explored influences mainly the role of environmental concern and green product attributes on actual behaviour. The proposed model is adapted from Theory of planned behaviour, built on the premise that environmental knowledge, environmental attitude and perceived consumer effectiveness leads to green purchase intention. But purchase intention and actual behaviour is mediated by environmental concern. Depending on the level of environmental concern which may be high or low the influence of green product attributes namely perceived relative advantage (cost benefit), perceived risks and product parity, on the purchase behaviour can be predicted.