Paper to be presented during the 5th Research week and International Conference to be held on, –22nd – 24th September, 2010 at EGERTON UNIVERSITY, KENYA . * Corresponding Author: Mwilawa, A.J (PhD Student) (Ajmwilawa@yahoo.com) Tel +255-787-892240Seventy two Tanzania indigenous cattle (36 Boran steers; 2-3 years old; initial liveweight 225 kg and 36 Tanzania Short Horn Zebu (TSHZ); 3-4 years old; initial liveweight 117 kg) were randomly allocated to three dietary treatments to study the effects of breed, diet and ageing time on carcass and meat quality characteristics. Animals were fed three different diets: grazing alone (Diet 1: control), control + 50 % ad libitum concentrate intake (Diet 2) and ad libitum hay + ad libitum concentrate intake (Diet 3). The concentrate contained 126 g CP and 13 MJ ME per kg DM. The steers were fattened for 90 days, slaughtered, and carcass and meat quality assessed. Boran had heavier (P<0.05) empty body weight, carcass weight and greater rib area than TSHZ (242 vs. 192 kg; 132 vs. 108 kg and 56 vs. 47 cm2). Animals fed diet 3 had higher (P<0.05) dressing percentage, carcass fat thickness, conformation score and normal meat colour score (54%; 2 cm; 12; 2.9) followed by Diet 2 (51%; 0.9 cm; 9; 3.7 and lastly Diet 1 (47%; 0.6 cm; 7; 4.4). In addition, longissimus dorsi (LD) muscle from animals fed Diet 3 had the lowest (P<0.05) shear force (45 N) indicating very tender meat whereas LD from animals fed diet 1 had the highest value (60 N) indicating less tender meat. Increasing post-mortem storage time from 2 up to 20 days decreased (P<0.05) shear force by 65%. It is concluded that both Boran and TSHZ cattle obtained acceptable range of meat quality values and that tender meat can be produced from indigenous cattle through feedlot finishing and post-mortem storage at refrigerated temperatures