Yagyas are rituals that are performed by Vedic Pundits (priests) for the purpose of working with karmas in the horoscope. Like gemstones and mantras, yagyas can be very effective at improving the quality of life.
During a yagya, a vedic pundit makes a fire and offers various substances into the fire while constantly chanting long, powerful mantras. The yagya can last from two hours for a very short one, to as much as a hundred days in some cases. In ancient India, these yagyas were not actually performed for individuals as much as for the society or the community. Kings would have yagyas done for the country. Great sages would sometimes do yagyas for helping mankind in some way. Communities would do yagyas to protection from harm or to help with the crops. Families would have yagyas done to have children or to create prosperity. In any case, the use of yagyas for individual purposes has been less common in the past. Recently, however, individual westerners have begun to perform yagyas for creating prosperity, good health, etc, with very good results. These rituals can be arranged at a person's home, but because of the scarcity of authentic Vedic Pundits in the West, most yagyas are done, with the recipient absent, in India. The fact that the recipient of the Yagya is not present does not seem to matter. In many cases, a yagya will be effective in dealing with a problem which a gemstone or a mantra is not able to help.
A good source for setting up a Yagya in India is the Vedic Yagya Foundation. This organization is trustworthy and has been setting up yagyas for westerners for many years. It also has reasonable rates.
To see a video of 9 planets yagya that was done at the World Conference on Mundane Astrology in Vishakhapatnam India in October of 2010, click on the video icon on the upper right sidebar.