In this study, the effects of local sour orange (Citrus aurantium), 'Taiwanica' (C. taiwanica), 'Yuzu' (C. junos), 'Troyer' and 'Carrizo' citranges (C. sinensis x Poncirus trifoliata), 'Cleopatra' mandarin (C. reshni), C. ampullacea, 'Kinkoji' (C. obovoidea) and 'Sanbokan' (C. sulcata) on some pomological characteristics of 'Star Ruby' grapefruit (C. paradisi) cultivar were evaluated under Adana ecological conditions. Fruit yield (kg/tree), fruit weight (g), height (mm), diameter (mm), juice content (%), rind thickness (mm), total soluble solids (TSS, %), total acid content (TA, %), TSS/TA ratio, fruit peel and juice color (hueo) were determined in order to see the effects of various rootstocks. The highest yield was on C. sulcata followed by 'Cleopatra' mandarin and sour orange. The largest fruit size was obtained from the trees on 'Carrizo' citrange, followed by 'Troyer'. The thickest fruit rind was in fruits from the trees on 'Carrizo' and the thinnest on 'Taiwanica' and sour orange. However, trees on the other rootstocks produced similar rind thickness without significant differences among them. There were significant differences between rootstocks as regards TSS/TA ratio. The highest was for fruits from the trees on 'Carrizo'. According to the hue data, red color in both peel and juice were the highest in the fruits on 'Carrizo' and 'Troyer' citranges.