Anterior knee pain is not a disease, but a syndrome with numerous causes. This paper describes its appearance in the patellofemoral joint in sportsmen and in untrained people. Chondromalacia patellae is a condition of the cartilage, not a disease, that is, it is never diagnosed alone. Relative muscular insufficiency, especially of the knee extensors, may occur in children and adolescents, as they grow rapidly. The consequence is a unbalance of active stabilizers and the disturbance of the slippery trail of patella, particularly in the presence of dysplasia of patellofemoral joint. The impingement syndrome pain occurs in sportsmen and people overloading the patellofemoral joint. Other causes of anterior knee pain should be excluded in clinical examination and slippery trail of patella, its position, and signs of instability should be determined. This paper gives an overview of patellar chondromalacia, lateral pressure syndrome, patellar subluxation, patellar acute and recurrent luxation, and idiopathic anterior knee pain. The treatment is basically conservative. Stretching exercises and the strengthening of certain groups of femoral muscles serves to regain the balance, thus normalising the slippery trail and taking off the burden from the patellofemoral joint. If conservative treatment fails, surgery is the alternative.