Antibody titre is an indicator of immune response of animal against vaccination. An experimental trial was conducted to evaluate the efficacy of a polyherbal immunomodulatory, antistressor, adaptogenic and rejuvenator product Restobal (supplied by M/S Ayurvet Ltd. Baddi, HP, India) in potentiating post vaccinal immune response against Blue tongue vaccination in Deccani lambs and sheeps. In the experiment twelve (142 days old) lambs were divided into two groups. Group C1: untreated control and group T1: treated with Restobal @ 10ml BID for 5 days pre and 5 days post vaccination and twelve (408 days old) adult sheeps were divided into two groups. Group C2: untreated control and group T2: Restobal @ 20ml BID for 5 days pre and 5 days post vaccination. The immune response potentiating efficacy of the product was assessed in terms of serum antibody titre against blue tongue virus. In addition the serum biochemical profile was also done. At the end of 28 days post vaccination, significantly high antibody titre was observed in treated groups as compared to control groups in both the trials. The results of the present experiment indicate the immune response potentiating effects of the Restobal in lambs and adult sheeps.