In order to achieve superior sales performance, salespeople need to be knowledgeable about customers' changing needs, increased market offerings, and various selling techniques. However, research has found that if a salesperson tries to process too much information within a limited time frame, he/she is likely to experience a phenomenon that is termed as Salesperson's Information Overload (SIO) and is detrimental to sales performance. As the term SIO has only recently been coined, it has not been well explored in personal selling and sales management fields, and no research has attempted to establish the linkages between SIO and the selling behaviours of salespeople. In addition, many studies show that to build and maintain strong buyer-seller relationships in order to achieve sustainable competitive advantage, salespeople need to adopt relationship selling behaviours which include Adaptive Selling Behaviour (ASB), Customer Oriented Selling Behaviour (COSB), and Relational Selling Behaviour (RSB). Since the emphasis of ASB is on applying different selling procedures in different selling situations, it is very likely to affect the adoption of COSB and RSB. Although there has been a significant amount of research conducted on each type of relationship selling behaviour and their impacts on sales performance, the relationship between ASB, COSB and RSB has not been investigated. Based on the above points, the present study examines the moderating role of SIO between different types of relationship selling behaviours, as well as between relationship selling behaviours and sales performance (behavioural and outcome performance). The study also attempts to establish linkages between ASB and the other two types of relationship selling behaviours (COSB and RSB). A framework is proposed to explain the relationships between SIO, relationship selling behaviours, and sales performance. The hypotheses were empirically tested in the present study by using appropriate statistical techniques. The results indicated that ASB has a positive effect on COSB and RSB. COSB is positively related to a salesperson's outcome performance, and RSB is positively related to behavioural performance. Surprisingly, the moderating effects of SIO were only found between ASB and RSB, as well as between the interaction intensity dimension of RSB and a salesperson's outcome performance. SIO did not show any significant effect on the other relationships between relationship selling behaviours and sales performance. This study can be considered as an important step in establishing the linkage between different relationship selling behaviours, and their relationships with a salesperson's behavioural performance and outcome performance. It establishes that salespeople need to follow ASB for better relationship selling behaviour adoption and sales performance. Although the impact of SIO was not found between relationship selling behaviours and sales performance, further research for overcoming the limitations of this study is suggested.