Thirty-two male fallow deer, half 18- and half 30-month-old, were slaughtered after a 4-month feeding trial on pasture alone or with daily supplement of 500 g (dry matter) concentrate/head (eight each 18- and 30-month-old). Neither diet nor age produced significant effects on M. longissimus thoracis et lumborum (LM) and on M. semimembranosus (SM) pH and colour. Meat texture properties (Warner-Bratzler-WB Shear Force and compression), water loss and collagen content were unaffected by diet, while the older deer had higher LM WB peak force values (4.15 vs 4.88 kg) and lower collagen solubility (34.61 vs 22.58%). LM and M. semitendinosus (ST) of the supplemented deer had a higher content of fat (pasture vs concentrate feeding: 0.56 vs 0.72% in LM; 0.55 vs 0.78% in ST) and provided lower PUFA, particularly n-3 PUFA, and higher n-6/n-3 ratio (3.30 vs 4.76 in LM; 3.39 vs 4.63 in ST). Thirty-month-olds' LM and ST were fatter than 18-month-olds', and provided lower PUFA, both in the n-6 and n-3 fraction.