There was a time when homoeopathy was very popular in Bengal, the " Nursery of Homoeopathy " in India. But there was dearth of books in Bengali on homoeopathy. So to spread homoeopathy among the people, who had little knowledge of English, a young Bengali gentleman Prafulla Chandra Bhar started a homoeopathic journal in Bengali titled "Hahnemann" and "Hahnemann Publishing Company" came into existence .

The need to supply quality homoeopathic medicines at a reasonable price was being felt constantly and therefore taking this in observance the company started a separate wing for Medicine in the year 1922. With passage of time this small beginning became gradually bigger and earned reputation for quality medicines. In the year 1930 the company started publication of an English journal on homoeopathy titled, "The Hahnemannian Gleanings", which gained international repute in due of time.

Until 1949 the company was mainly manufacturing potentized preparations such as dilutions, triturations and tablets prepared from imported back potencies and at the same time was also importing mother tinctures from the U.S.A. After the Second World War, a scheme was prepared to manufacture mother tinctures and back potencies strictly on Hahnemannian principle, i.e. each potency in a separate phial. To get superior quality alcohol for these activities a separate unit was started for repurification of commercially available rectified spirit.
 
With the view to better administration of the growing activities, during the year 1955, the firm was converted into a joint stock company and was christened as Hahnemann Publishing Co. Private Ltd.

During the year 1956 preparation of 50 millesimal scale potencies, the last innovation of Hahnemann, was undertaken on a commercial scale. In 1973 a new factory was started at Titagarh in the vicinity of Calcutta on a 2.5 acre of land in an eco-friendly environment full of greeneries and water bodies and a major portion of the manufacturing facilities were shifted there.

At present the company is engaged in manufacturing large number of mother tinctures, potentized preparations (decimal, centesimal and 50 millesimal potencies, triturations and tablets), ointments etc. with latest machines and as well as publishing various types of books on homoeopathy. A very well equipped quality control department with most modern instrumental facilities like absorption spectrophotometry, chromatography, polarimetry, photomicrography etc. for manufacturing quality homoeopathic medicines is engaged in testing of raw materials to be used for preparation of medicines as well as the finished preparations. Importance of quality of packing material as well as their proper cleaning and sterilization also gets importance in these activities. As a result the medicines produced by Hahnemann Publishing Co. Private Ltd., popularly known as "HAPCO" within the profession, is considered as one of the best homoeopathic medicines ever prepared and this makes HAPCO quality medicines as one of the most sought after homoeopathic medicines not only in India but in the European countries as well.