Concerning the analgesic and anti-inflammatory effects of combination of Vitamin B12 with other B Vitamins or traditional drugs, this study was designed to evaluate the effect of Vitamin B12 alone on nociceptive pain, inflammatory pain and inflammation. Total 24 male Long Evans rats (225±25gm) were taken care according to international guidelines on use of laboratory animals and divided into two groups. Single supplemented rats (n=12) were intraperitonialy treated with a single dose of 15 mg/kg B12 (n=6) or equal volume (15 ml/kg) of normal saline (n=6). Similarly chronic supplemented rats (n=12) were divided into normal saline (n=6) and B12 (n=6) groups with same dose and route of treatment per day for consecutive 7 days. Analgesia was assessed by warm water (±55 degree Celcius) tail immersion test (Steinmiller and Young 2007) followed by formalin test (50 μl of 2% formalin, subcutaneously) using a modification of the original formalin test protocol (Dubisson and Dennis, 1997). Euthanasia was done by di-ethyl ether (99%, 10-12ml) followed by decapitation (Zschenderlein et al. 2011) and anti-inflammation was measured by water plethysmometry (Fereidoni et al. 2000). The data were expressed as mean±SEM and analyzed by independent sample ‘t’ test. The single supplementation of vitamin reduced the nociceptive pain (%MPE=4.56±1.05 vs. 4.27±1.59; jerking frequency/5min in early phase=89±3.79 vs. 101.5±4.40; flexing+licking duration in seconds/5min in early phase=247.33±10.62 vs. 260.33±6.93) nonsignificantly, inflammatory pain (jerking frequency/5min in late phase=69.28±2.40 vs. 75.44±1.26, p<0.001; flexing+licking duration in seconds/5min in late phase=277.57±2.16 vs. 288.85±2.59, p<0.01) and inflammation (ml of edema volume=0.16±0.02 vs. 0.23±0.02, p<0.01) significantly. Similarly, chronic B12 supplementation reduced the nociceptive pain (%MPE=7.08±1.3 vs. 3.85±1.55; jerking frequency/5min in early phase=86.5±3.42 vs. 87.5±5.75; flexing+licking duration in seconds/5min in early phase=243.5±7.1 vs. 260.17±6.16) nonsignificantly, inflammatory pain (jerking frequency/5min in late phase=64.07±2.07 vs. 84.65±2.45, p<0.001; flexing+licking duration in seconds/5min in late phase=275.89±1.88 vs. 289.91±1.77, p<0.01) and inflammation (ml of edema volume=0.11±0.02 vs. 0.23±0.02, p<0.01) significantly. In addition, in all study variables a better trend of decrement was found in the chronic supplementation. The study reveals that vitamin B12 may possess effective role against nociceptive and inflammatory pain, as well as inflammation, and chronic supplementation may be better useful than the acute one.