Pig meat quality is influenced by interactions between genotype, rearing factors, preslaughter and slaughter conditions. This paper describes muscle characteristics, in particular muscle fibers, intramuscular fat and connective tissue and their relationship with sensory, technological, nutritional and hygienic traits of meat. Although some relationships are well established, such as the favorable effect of intramuscular fat level up to 3% on sensory properties, the influence of muscle fiber characteristics (metabolic and contractile type, diameter) on the different components of meat quality is not fully understood. The identification of muscle traits that are favorable to meat quality, and a better knowledge of the mechanisms leading to the differentiation and development of muscular tissues are required, in order to produce meat that satisfies consumers as well as the meat industry.