Like Christianity and Islam, Buddhism is a missionary religion in that it has always believed that the truth it teaches should be made known to as many people as possible. After the Buddha made and trained his first disciples he gave them this commission: "Go ye forth for the good of the many, for the welfare of the many, out of compassion for the world. Let no two of you go in the same direction, teach the Dhamma that is beautiful in the beginning, middle and end, expound both the spirit and the letter of the holy life completely fulfilled, perfectly pure. There are beings with but little dust in their eyes, who not hearing the Dhamma will decline but who, if they do hear it will grow". However, the strategies and techniques that the Buddhist missionaries have used in conversion have always been markedly different from those of some other faiths. Both now and in the past Buddhist missionaries would arrive in an area, usually on invitation, and begin teaching those who came to listen to them or translating text into local languages. They usually also tried to find common features with the already established religion rather than oppose it. Buddhist missionary endeavour is therefore usually gentle, unobtrusive and a response to a need rather than the creating of a need.

After the Buddha's direct disciples themselves, the next significant Buddhist missionaries were those sponsored by King Asoka who were sent to all the religions of India, Sri Lanka and Burma and to as far away as Libya, Egypt and Syria. The last great Buddhist missionary success was the conversion of the Buriats and the Kalmaks in the Russian Far East by Tibetan monks in the 18th and 19th centuries. The first modern missionary to the West was the Sri Lankan, Anagarika Dhammapala at the end of the 19th century. Today Buddhist missionaries from many countries are now actively working in the West and although the signs look encouraging so far it remains to be seen what the long term results of their endeavours will be.