The purpose of this paper is to empirically verify if the possible existence of scale economies actually supports the argument that municipal consolidation is needed in Slovenia. The major reform of local self-government in Slovenia was implemented in 1994, when the transformation of existing 58 »communal« municipalities was envisaged. From 1995 onwards, the number of municipalities increased to the current number of 212 municipalities. Consequently, the necessity to implement structural reforms of local self-government in Slovenia has been stressed. The arguments favoring municipal amalgamations stressed that country has become too fragmented and municipal amalgamation would enable the reduction of (administrative) costs, and increase efficiency as well as quality of services provided, indicating that technical aspects of local government operation are targeted. Following, technical efficiency of Slovenian municipalities is estimated with the Data Envelopment Analysis (DEA) method, in order to determine if (and which) municipalities are experiencing increasing returns to scale (i.e., scale economies). The results indicate that there is important scale efficiency component, and predominantly very small municipalities are experiencing economies of scale, but their number is relatively low. Therefore, one of the classical arguments for municipal amalgamation, achieving economies of scale, can only be applied at a limited scale. This does not imply that more extensive amalgamation is not warranted, but it demands that other arguments justifying municipal amalgamation should be presented.