This study aimed to test new diet formulae based on full fat soybean destined to Arbor Acres broilers fattening. A sample of 520 chickens, divided into two groups was used: M-Group, fed with a diet containing maize, soybean meal, oil and fish meal and FFS Group, fed with another diet mainly containing full fat soybean and other components. The diets have been elaborated in three alternatives for each fattening stage: starter, grower and finisher. During the fattening, the main parameters have been recorded and compared between the two groups: daily and total live weight gain, daily and total food consumption, as well as feeding and fattening costs. A number of 8 fattened chickens were slaughtered and we also determined slaughter output, the components of carcass, the chemical composition of chicken meat and the ratio between saturated and unsaturated fatty acids. The FFS plot recorded higher fattening performances, that is a higher daily and total gain, a lower food consumption, but also lower feeding and total costs in comparison with the other group. We have noticed that FFS diet assured an increased crude protein percentage inside chicken meat and a more convenient ratio between the fatty acids, in favour of the unsaturated ones, resulting to a high meat and fat quality.