Abstract Purpose: To carry out a modern diagnostic survey among patients with a clinical and radiological diagnosis of early osteoarthritis of the knee. Materials and methods:A magnetic resonance imaging survey was performed on 70 patients (82 knees) with a mean age of 59 years. (range, 40–71 years) who had chronic knee pain, clinical diagnosis of early osteoarthritis of the knee and conventional knee radiographs classified as 1 and 2 on the Kellgren–Lawrence scale. Results: A variety of different disorders was found; degenerative meniscal lesions with or without ruptures of the anterior cruciate ligament in 70.7% of the knees, osteonecrosis of the femoral and tibial condyles in 9.75%, osteophytes and degenerative articular cartilage lesions in 8.54%, transient osteoporosis in 2.44% and benign neoplasms and cysts in 6.1%. Conclusions: The existence of such a heterogenous group of disorders in these “early osteoarthritic knees” may explain failures in treatment and it may justify a modern MRI imaging approach to proper diagnosis.