In the last decade, a growing demand of consumers for improvements in pork meat quality and an increased interest in animal welfare has led to the development of alternative pig production systems, such as outdoor rearing. Up to now, several studies have been conducted to characterise autochthonous pig breeds in the Mediterranean area(Iberian, Gascon, Nero Siciliano and Cinta Senese) being raised in outdoor production systems. The main purpose of these local pig breeds is the fabrication of high quality dry-cured meat products taking advantage of their rusticity and the natural feed resources. The knowledge of the performance of modern pig genotypes in outdoor conditions is very limited probably due to lack of economic benefit. However, it might be worth testing them in regions rich in grass, shrubs and trees, where no local breeds are raised and if a differentiated quality of their end products can be demonstrated. The current book tries to review some of the factors that affect carcass characteristics and meat and fat quality of heavy commercial crossbred pigs reared outdoors. Recent trials carried out in Spain have been used for it.