ABSTRACT ** : The purpose of this paper is to assess whether financial performance differences between labour‐managed (LOFs) and mercantile (PCFs) firms are due to differences in their capital‐ownership configuration or to the particular measurement indexes commonly used to quantify performance. The empirical evidence rests upon a 1994–2003 data set of LOFs and PCFs that operate in the Industrial and Services sectors of the economy of Navarre, Spain. The results do not detect significant differences in financial performance between LOFs and PCFs, especially in the long‐term and suggest the need to develop performance indices more akin to the special nature of the LOFs.