Purpose – The purpose with the study is to get an understanding of how a low-power retailer can incentivize their high-power supplier(s) to improve their supplier on-time delivery performance. The purpose was fulfilled by answering the two research questions: How does power asymmetry influence supplier on-time delivery performance in a low-power retailer and high-power supplier context? How can low-power retailers work with high-power suppliers to increase their supplier on-time delivery performance? Method – To answer the research questions, both theoretical and empirical data was required. A literature study was conducted to gather relevant theories about on-time delivery performance and supplier relations. To get the required empirical data, a case study was conducted at a case company that suited the subject. The case study consisted of multiple interviews and document studies. This enabled for an analysis in the form of pattern matching in order to answer the research questions and thereby fulfill the purpose. Findings – The power asymmetry between a supplier and a retailer influences the supplier on-time delivery performance in several ways. The low-power retailer can experience difficulties with setting the demands they need. Having to deal with high-power suppliers while being a low-power retailer has its challenges when a satisfying level of supplier on-time delivery performance is needed. The study found four appropriate ways for low-power retailers to work with high-power suppliers to get improved supplier on-time delivery performance. Improvement and changes can be done, these could be major and minor, internal and external. Implications – Both practical and theoretical implications have been provided. The practical implications are that the low-power retailer needs to know their power position in the dyadic relation and act accordingly to enable for a satisfying level of supplier on-time delivery performance.The theoretical implications are that this study has filled a knowledge gap regarding improvement of supplier on-time delivery performance. The knowledge gap would be the power asymmetry subject from a low-power retailers’ perspective. Not much attention has been devoted into this subject.Limitations – The limitation with this study was conducting a case study. The results are limited to this type of telecommunication retailing company. The case study was the choice of method as it gave a deeper understanding for the subject. Keywords – On-time delivery performance, supplier relations, power asymmetry, dyadic relationships