Interlocked relationships are characterised by traders’ supply of inputs and cash to producers on credit, to be reimbursed at sale time based on pre-defined prices which are often lower than the prevailing market price. The study analyses determinants of choice for interlocking in the gum arabic sector in Senegal and the effect of interlocking on gum production and market participation; gum arabic is a natural exudates of Acacia Senegal trees that grow in the semi-arid lands of Africa. Data from 422 gum producers in Northern and Eastern regions of Senegal are used. About 45percent of respondents are involved into interlocking with village shop-owners or mobile traders. Interlocking has a negative effect on prices received by gum collectors. However, in the absence of effective credit markets, interlocking positively influences market participation and production as found through a two-step Heckman selection model by the provision of market assurance and safety for emergencies.