This study describes the organization of the primary Sandinista counterinsurgency organizations, the tactics they employed against the Contras, and the influence of many factors in the development of these organizations and their tactical doctrine. These include; the Sandinista's experience as guerrilla fighters, the military influence of the Soviet Union and Cuba, the impact of the Contra and U.S. military threats, the military aspects of terrain and weather, and the effects of tactical and strategic time factors. Much of the material is from primary sources, and the study contains original tactical diagrams derived from these sources. The study concludes that the Soviets and Cubans played a central role in shaping these tactics and organizations through their military advisers in Nicaragua and with the provision of substantial military equipment. Nonetheless, the other factors above caused the Sandinistas to modify the Soviet/Cuban doctrine to their own needs.