Progressive arthropathy of large joints of the limbs (knees, ankles, elbows), resulting from recurrent joint bleeds and subsequent long-term degenerative phenomena, is one of the main causes of morbidity and of deterioration of quality of life in adult severe hemophiliacs. While primary prophylaxis (i.e. the regular continuous long-term infusion of factor concentrates started before the age of two years and/or after no more than one joint bleed) is nowadays considered the gold standard for preserving joint function in patients with severe haemophilia, the benefits of secondary prophylaxis (i.e., all the long-term regular treatments not fulfilling the criteria of primary prophylaxis) are still controversial. In this review we present the literature data on secondary prophylaxis, focusing on adolescent and adults haemophiliacs along with clinical experience in Italy. On the whole, the more recently published studies suggest the effectiveness of early and delayed secondary prophylaxis. However, a number of questions are still unanswered, including the optimal dose, dosing interval and duration of secondary prophylaxis. Only large, prospective, long-term, possibly randomized studies will help to definitively assess the clinical impact of this strategy in adolescent and adult hemophiliacs.