The territory of the commune of Frasne is surrounded by those of the communes of Bonnevaux, Bouverans, Dompierre-the-Limes, Boujailles and Courvières (Doubs), like by that of Level-of-Fourg (the Jura).
Its territory extends on 3 287 hectares. It is crossed by a brook, is called Noirbief or Lotaud, which is an affluent of Drugeon. Some ponds meet in the south-east of the village: the large pond (or pond Square, of the name of its owner), the Lucien pond (communal), the pond of the Mill (communal) or the Vanthier pond (private).