Tenderness is, undoubtedly, the most important single meat quality trait. Variation in meat tenderness is the main factor for consumer dissatisfaction; hence this trait must be controlled in order to improve customer satisfaction and decision to repurchase. Variation in beef tenderness may be attributed to breed (genetic status), carcass composition, and environmental factors (chronological age, time on feed, implants and ante-mortem stress). Many post-mortem treatments like ageing, electrical stimulation, chilling rate, and post-mortem tenderization technologies also affect tenderness. Carcass fat proportion, especially intramuscular fat (marbling), plays an important role in the meat sensory characteristics, since it contributes directly to its sensory proprieties. Expedite methodologies to predict meat tenderness on the live animal or at slaughterhouses level have been developed to satisfy the consumer demands. Variation in meat tenderness is also greatly affected by the selection. Among different breeds, genetic evaluation programs are being developed, and the current research is focused on genes with major effects on meat tenderness and marbling.