Introduction The adequate, pathogenetically substantiated pain management is essential for treatment of early stages of deforming osteoarthritis of the knee joint. There is a need to explore the effectiveness and mechanisms of modern methods of electrical therapy and their impact on the quality of life due to close cause-and-effect relationship between the pain, inflammatory and destructive components of osteoarthritis (OA) as one of the most common conditions.The objective was to evaluate the effect of interstitial electrical stimulation (IES) as a monotherapy in the course of conservative treatment of early stages of gonarthrosis based on clinical and biochemical findings.Materials and methods Radiographic findings, skin electrometry (objective parameters of pain intensity), limb weight-bearing capacity, biochemical parameters of connective tissue matrix degradation in blood serum and 24-hour urine samples, and treatment satisfaction were explored in 43 patients. Patients who received a course of IES were assigned to the treatment group (n = 22) and patients who received standard treatment without IES constituted the control group (n = 21).Results Electrometric analysis showed a higher effectiveness of pain relief in the treatment group compared to the controls with asymmetry coefficient measuring 3.2 ± 0.31 versus 1.9 ± 0.4 at p > 0.05. The weight‑bearing scored 3.59 ± 0.34 versus 3.26 ± 0.2 at p > 0.05. The treatment group showed shorter treatment length with 13.21 ± 1.2 days versus 18.3 ± 1.2 days in the control group at p > 0.05 and a higher degree of satisfaction with outcomes scored 96.2 ± 2.59 in the treatment group versus 86.2 ± 3.17 in the control group. A statistically significant difference (p > 0.05) was established in the levels of free and total hydroxyproline characterizing the different intensity of collagen breakdown in the groups at the end of treatment.Discussion The IES used as an analgesic and anti-inflammatory therapy was shown to be highly effective with changes in the hydroxyproline level in the media suggesting a chondroprotective effect. The analysis and comparison of objective parameters demonstrated high effectiveness of IES in the treatment of early stages of gonarthrosis in middle-aged and elderly adults.Conclusion The IES used for treatment of early stages of gonarthrosis helps pain reducing the intensity of collagen destruction and improving weight-bearing.