The objective of this study is to examine the digital transformation of the complete population of 24 Spanish food units, named Mercas. We develop an index that gauges the degree of digital transformation of these public sector companies. Using a Tobit panel data model, we identify the main determinants of the Mercas’ digital transformation status. Our findings suggest that the size of the Merca, the proficiency of digital technologies by top management, the cooperation between the millennial generation staff and the remaining staff, the business management of buying and selling flowers, fruit and vegetables, and meat, and the utilization of B2B platforms for transactions and information exchange with wholesalers are some of the key determinants of digital transformation. The study also emphasizes the significance of customer demand for the implementation of new technologies as an external factor that influences digital transformation.