Background: Visfatin is a one of the recently discovered adipokine that has important pro-inflammatory and catabolic roles in rheumatoid arthritis (RA). Pro-inflammatory cytokines initiate a number of physiological changes that result in the characteristic signs of inflammation. Visfatin may play a role in OA by activating chondrocytes. Along with its cytokine effect, visfatin has an enzymatic activity called nicotinamide-phosphoribosyl-transferase (NAMPT). Objectives: To study the level of Visfatin in RA and OA sera and correlate its levels with activity and severity scores of both diseases. Subjects and methods: A case control study was conducted to assess Visfatin serum level in 20 patients of osteoarthritis and 25 patients rheumatoid arthritis and 20 apparently healthy individuals. Lequesne's algo-functional Index used for assessment of OA functional impairment , Kellgren and  Lawrence  for radiological severity and KOFUS for activity , while Larsen's scoring system used for assessment of RA severity and DAS 28 score for activity. Visfatin concentrations in serum measured using a commercially available ELISA kit. Results: Mean Lequesne's index was 11.2 ± 3.6. According to Kellgren and Lawrence we had one patient G1 , 9 patients GII , 7 patients GIII and 3 patients GIV .Median KOFUS was 5 and it ranged from 3 to 13,. Mean DAS 28 was 4.96± 1.27.  As regards Larsen score, mean was 24± 22. There was an overall significance in visfatin between three groups. P value was Conclusion: Visfatin may have a role in the pathogenesis of OA and RA. Furthermore it acts as a potential marker for disease activity and severity of RA as well as severity of OA.