This paper aims to identify the factors that affect the decisions of managers of manufacturing sector SMEs in Iran to utilise external accountants' advisory services and to examine the effect of these advisory services on SME performance using the Resource-Based View (RBV) of the firm as the theoretical lens in the Iranian SME manufacturing sector. A questionnaire survey of 658 Iranian manufacturing SMEs is used. The results of linear regression analysis suggest that the use of external accountants′ advisory services is positively associated with the knowledge of owner/manager, technical competence, competitive intensity and complexity of market decisions. In addition, the study evidences that the use of advisory services has a positive effect on SME performance. Furthermore, after controlling for age and size of the firm, the relationships between four independent variables (knowledge, technical competence, competitive intensity and complexity of market decisions) and utilisation of advisory were remained significant.