The aim of the present study was to investigate the relationship between CRP and clinical parameters of the disease, including quality of life of patients with knee osteoarthritis (KOA) in Bulgarian population. 132 patients (81% female) with symptomatic KOA (mean age of 63.45 years) and 31 healthy volunteers were included in the study. Their clinical characteristics were evaluated using the following questionnaires and scales: Visual Analogue Scale for pain (VAS), Lequesne Algofunctional Index, Western Ontario and McMaster University Osteoarthritis Index (WOMAC), Health Assessment Questionaire – Disability Index (HAQ-DI). CRP levels were measured in all participants. Patients with KOA had higher levels of C-reactive protein than the controls; however, CRP levels remained still in laboratory reference ranges. CRP levels correlated with pain assessed by VAS in the patient group. Groups of patients with elevated CRP values and normal CRP values differ statistically significant in their age, perceptions of pain assessed by VAS, disease activity and quality of life. CRP is a useful indicator in patients with KOA, which reflects pain and disease activity in general