As animal welfare has become a major societal concern since the last decades, identifying the factors affecting it, is of first importance. Many studies have been conducted, mostly centred on one particular environmental factor. However, animal welfare is multifactorial, and evaluating the management as a whole seems more appropriate. In this particular study, we aimed to identify environmental parameters impacting riding school horses’ welfare. We focused here on four reliable welfare indicators (presence of wounds, stereotypic/abnormal repetitive behaviours, ear position and depressed-like posture) and recorded sixteen intrinsic (e.g. sex, age, type) and extrinsic (housing, feeding, social and working conditions) factors of impact. Using logistic regression models, we could identify and classify the management parameter according to their impact on the different welfare indicators and we were able to identify characteristics of good and bad management practices. Besides confirming the importance of feeding and housing conditions, our study is the very first to show that working conditions in developed countries have a crucial impact on several aspects of equines’ welfare, and that horses might be less resilient to inappropriate living conditions than ponies. This study leads to the identification of characteristics of “good” and “bad” management practices as a whole, based on scientific evidences on a large sample of horses.