Opium is a drug being used in modern medicine as well as in homeopathy. Despite of the same source, both the pathies have different principles and indications. Opium is an alkaloid having main action on CNS. So in this study, we evaluated the effect of different dilutions of Opium in homeopathic potencies on CNS in mice and compared with that of Pentazocine. We divided forty mice of either sex into 7 groups (6c, 30c, 200c, 1 M, 0/1 LM, dispensing alcohol, Pentazocine). Test drugs were given orally. Different actions on CNS were evaluated by using Actophotometer for locomotor activity, Analgesiometer for analgesic activity and Straub test for opioid. Our result showed that pharmacological actions of Opium seen in modern medicine were not seen with different dilutions of Opium, in homeopathic potencies. 30c and 200c dilutions may be having secondary curative that is CNS stimulant action (reversal of CNS depression due to alcohol) as per homeopathic principles.