This is the single blind comparative clinical trial to determine the internal administration of rhizome of Calamus rotang powder in the management of Azhal Keelvayu. According to Siddha system Azhal Keelvayu is one of the 10 types of Keelvay which included under the Vatharogam. The sign and symptoms of Azhal Keelvayu similar to osteoarthritis of the knee joint. Further the study was investigated to determine the effectiveness of the drug with different dosage, the side effects and the associated factors between the Azhal Keelvayu. Thirty patients were selected and who were divided into three groups and named as Group A, B and C and the groups treated with 0.5g, 1g and 2g of Chooranam internally three times per day with lukewarm water for 40 days. Paired‘t’ test was used to test the significance of treatment using before and after treatment. At the end of the treatment Calamus showed highly effective. Dose effectiveness as follows: 2g of Chooranam shows significant and markedly improvement on 20th and 40th day of treatment compare to 1g and 0.5g.1g shows markedly improvement on 20th and 40th day, the dose effectiveness comparably less than the 2g and more than the 0.5g. 0.5g shows moderately improvement on 20th and 40th day, the dose effectiveness comparably less than the dose of 2g and 1g.Symptoms were increased with particular foods and seasons and the side effect was comfortable in defecation. Based on the results it provides successful proof of the traditional literature about the Calamus rotang.