Progression of rheumatoid arthritis (RA) and osteoarthritis (OA) is associated with inflammation and oxidative stress. Previous studies have shown that there was no difference between RA and OA patients regarding the percentages of the different lymphocytes subsets reflecting the abnormalities in T cells and its subsets that may contribute to the pathogenesis of OA as in RA. Therefore, the present study was aimed to analyze that whether disease activity of OA is able to affect a few serological and biochemical parameters in the same way as RA does or differently. The study was done on 36 asymptomatic controls (25 women), 28 patients with OA (20 women), 36 patients with RA (22 women). Patients with OA were screened according to radiological and clinical finding of Kellgren and Lawrence grade and ACR criteria and assessed by VAS and WOMAC score. Patients with RA were selected who were fulfilling 4/5 symptoms of ACR criteria, and their DAS28-CRP, VAS score, and RF positivity were evaluated. Participants of the groups were matched for sex, age, weight, and height (body mass index). The BMI of all three groups was also found to be the same (P > 0.05). The mean level of LDL, cholesterol, MDA, CRP, and triglyceride was significantly (P < 0.05 or P < 0.01) higher in both OA and RA as compared to control. The mean level of total lipid, cholesterol, MDA, CRP, and triglyceride was found to be significantly (P < 0.05 or P < 0.01) higher in RA as compared to OA. The pre-treatment CRP level of both groups of patients showed significant and direct relation with total lipid (r = 0.27, P < 0.05) and cholesterol (r = 0.66, P < 0.01). Inverse relation was observed between uric acid and creatinine (r = -0.26, P < 0.05) and cholesterol and HDL (r = -0.34, P < 0.01). Our study shows the similar trend in lipid profile and other parameters studied in both patients with OA and patients with RA with more pronounced changes in RA.