Purpose - The purpose of this paper is to focus on the identification of barriers to the implementation of benchmarking initiatives. Managers have little guidance on strategies for successful implementation and face difficulties in anticipating problems. The main objective of this paper is to provide a better understanding of typical barriers that occur in a specific type of benchmarking: internal benchmarking. Design/methodology/approach - This paper systematically develops a categorized list of barriers to internal benchmarking based on the literature; and validates and enriches them with an in-depth case study of an internal benchmarking initiative. Findings - Barriers to internal benchmarking initiatives of different types are found: organizational barriers (people, culture, and context), benchmarking project management barriers (planning and implementation, leadership, and business pressures) and benchmarking data barriers (difficulty to access/compare data). Future studies might take these categories as a solid starting point in furthering the understanding of barriers to benchmarking. Research limitations/implications - The exploratory nature of the paper limits its generalizability. Practical implications - The paper paves the way for the process of devising strategies to overcome the identified barriers. This is especially relevant because few studies to date have focused on these issues and benchmarking practitioners have insufficient knowledge to anticipate and overcome benchmarking-related problems. Originality/value - This paper contributes to theory building on the implementation of benchmarking in general; and on barriers to internal benchmarking initiatives in particular.