The goal of this research work was to characterize carcass, meat quality traits, proximate composition and lipid profile of cull beef cows reared in extensive systems across various seasons. Mature beef cows (n=65) with mean age of 14.12 years and culled from commercial farms were slaughtered in the Spring, Summer, Autumn and Winter, after a finishing period of about 4 weeks. The meat quality traits were analyzed at 7 d postmortem in Longissimus thoracis, Longissimus lumborum, Semimembranosus, Psoas major and Semitendinosus muscles. The highest carcass yield was obtained in Winter (P <0.05), but the Intramuscular Fat (IMF) means were similar in the different seasons. The meat samples showed high average Warner-Bratzler shear forceWBSF (between 5.41-6.86kg), which may be considered as tough (according to the scale used), except for the Longissimus thoracis which showed intermediate average (5.13kg). However, Psoas major obtained the highest overall acceptance scores. Samples of meat from animals kept in extensive system, natural conditions of Southern Portugal, present high amounts of n-3 PUFA. In Autumn and Summer, portions of 100 g/day of meats with 4.03% and 4.25% of IMF with 1.12 and 2.20% of n-3 PUFA in total fatty acids, can provide between 72.96 and 143.31mg of n-3 PUFA or 31.99 and 61.21mg/d of EPA plus DHA, which corresponds to 12.47% and 24.48% of the requirements recommended by EFSA authorities (250mg/d of EPA plus DHA).