The article covers the problem of non-Moslem people recruitment for extremist and terrorist organizations which is held in places of detention. On the basis of the study of biographies of 100 newly Islamite converts, convicted or put on the wanted list for extremist or terrorist crimes, authors state that 8 % of the abovementioned newly converts have obtained their destructive beliefs in the places of detention. Two main ways of the convicted involvement into extremist and terrorist organizations are defined in the article - traditional Islam adoption under the influence of cellmates with the following convert to Wahhabism or instantaneous Wahhabist ideology adoption.The authors pay special attention to the main methods of newly converts recruitment - the opposition of their own law to the «law of the underworld» with a possibility to create an alternative prison hierarchy (as a rule in case of successful assertion of a «Wahhabist law» above the «law of the underworld» the recruitment process becomes more intense), pressure from au- thoritative cellmates, willingness to enter the Wahhabist community as well as mercenary motive - support and protection from the members of «prison jamaat», special diet and working hours. The cases of Islam adoption by the prisoners serving whole- life tariffs and prisoners who have never contacted the recruiters are also considered in the article.The authors note enhanced activity of the recruiters in this area specifically among the largest terrorist organizations and suggest some ways of counteraction to this threat. One of the conditions of solution of the given problem is a balanced approach to the involvement of Muslim clerics to work with prisoners, as is not always the Muslim clergy professes traditional Islam. Moreover, periodically, the persons having the official status of a Muslim religious leader involved in the Russian Federation the criminal responsibility for extremism and terrorism.Another measure in addressing the problem of «prison Jamaat», with observance of necessary safety measures and improving interagency cooperation may be the creation of a separate jails for radical Islamists.