The results of Rb-Sr datings of two reddish to reddish grey microcline-rich granites, the Segmon and Gösta granites, from the Gneiss Complex of south-western Sweden are presented. The granites have previously been dated with the U-Pb method on zircons. The Rb-Sr age of the Segmon granite is 1250 Ma, which is identical with the zircon age. The initial87Sr/86Sr-ratio is 0.7107. The Rb-Sr isotopic system of the Gösta granite is profoundly disturbed. The best-fit reference line (MSWD = 3.1) corresponds to an age of 1423 Ma, which is 154 Ma less than the zircon age. The Rb-Sr date has probably no geological significance. These data fit the general pattern of Rb-Sr isotopic characteristics of the ensialically formed granitoids in the Gneiss Complex. According to this pattern, rocks older than c. 1250 Ma frequently have disturbed systems whereas younger rocks often yield primary isochrons.