If horses should be given daily opportunity to spend free time outside in paddocks is of constant debate among those involved with horses. In this book we follow 841 horses of different breeds and categories, in the design of a cross-sectional study, during a period of 2 years. We investigate if there is any basis for the most common concerns, namely risk of injuries, when keeping horses in paddocks. Moreover this book covers a wide range regarding stable environment, management and animal health. Special interest aims at investigating whether lack of free time spent in paddocks, possibility for social contact between horses, time budget for feeding given as well as keeping horses on muddy grounds affects the prevalence of behavioural disturbances (wood-chewing, crib-biting, weaving and box-walking) and the health of the horse (problems related to the hooves/legs, respiratory- and digestive systems). Together with a solid literature review the revealing facts from this research, presented easily comprehensible, should be equally useful to professionals working in the field of horses as well as anyone else who want to enhance horses Quality of Life.