The main purpose of this study was to analyze the relationship between clinical symptoms and roentgenographic changes in patients with incipient osteoarthritis of the knees (OA). One hundred and sixty-two patients (126 women, 36 men, mean age 59 years) with established osteoarthritis of the knee were examined. Patients performed subjective self-assessment using Lequesne's questionnaire (index of severity for OA of the knee) and had frontal and lateral roentgenograms of both knees. Validity of the indices as reflections of individual symptoms was documented. A statistically significant correlation was found between clinical and patient indices (r = 0.327, p < 0.0001) as well as a very weak correlation between the clinical and roentgenogram indices (r = 0.196, p = 0.286). However, there was no correlation between the patient index and roentgenogram index (r = 0.065, p = 0.47). For the assessment of severity and progression of the disease, items reflecting acute irritation (swelling, effusion, increased joint temperature, pain during passive motion) were more reliable than items reflecting chronicity (muscular atrophy, decreased range of motion, crepitus). This study confirmed that Lequesne's questionnaire is a suitable tool for assessing subjective symptoms as well as for generating a condensed measure of disease severity. In addition, sclerosis, narrowing and osteophytes were proved to be important features characterizing the OA process.