In this paper we have examined the scale and cost inefficiency of a sample of Swiss electricity distribution utilities. To do so, we have considered estimation of a stochastic frontier average cost model using the approach suggested by Schmidt and Sickles (1984) for panel data. A translog cost function was estimated using panel data for a sample of 30 municipal utilities over the period 1992-1996. The results indicate the existence of economies of output and customer density and economies of scale. Moreover, the findings on cost inefficiency show that a majority of the distribution utilities is not producing at the minimum level of the cost and that a possible application of the frontier methodology employed in this paper relates to the regulation and benchmarking of the delivery rates.