Salesperson performance is essential to commercialise and sell a new product in the market. It is significant to investigate determinants that affect salesperson performance while selling new products. Theories of reasoned action and perceived behavioural control were examined, which in turn shed light on different factors including attitude, self-efficacy, subjective norms, product and customer knowledge. Using the quantitative approach and survey method, the study attempted to obtain a clear insight of the determinants of salesperson performance vis-à-vis new product selling. Purposive sampling was used to select a sample which comprised of salespeople in a business-to-consumer market. The results indicated significant positive relationships between salesperson performance and positive attitude, high self-efficacy and knowledge about products and customers. Moreover, a highly positive correlation was found between the subjective norms and salesperson performance. This research proposed recommendation that managers focus on increasing salesperson knowledge about new products and customers, while boosting self-efficacy and positive attitudes towards selling a new product.