Every year, the Swedish Armed Forces and the Swedish Defence Material Administration, jointly carry out a number of underwater blasts. According to the Swedish Environmental Code, people running businesses or operations must have a sound knowledge of environmental effects in order to ensure human health and protect the environment. The aim of this literature study is to summarize the environmental effects of underwater blasts, and also to give an overview of methods limiting the negative consequences. When it cvomes to the environment, blasts carried out in water can generate two types of scenarios; damages due to physical effects caused by the detonation, or those caused by the explosives themselves and their reactions products by means ot toxic effects or the releasing of particles. The danger zone for underwater blasts is larger than that for air blasts. However, one tends to underestimate the effects of underwater blasts since they are not immediately established. There are a number of steps to be taken in order to prevent the environmental damages of underwater blasts. Firstly, the use of alternatives to regular blasts must be investigated; the potential usage of simulation, dummies and blasting basins or tanks. Considering the environmental aspects, knowledge of the underwater environment as well as of the topography in the blasting area is of importance. Secondly, it is important to ceasing all blasting activities during biological-sensitive periods. it is recommended that environmental authorities and research agencies cooperate with each other. The technical steps to keep negative consequences down can be complicated to take practically. The use of air bubble curtains is probably the most advisable. Repulsing sounds can also be of interest, but have not been evaluated in connection with blasting. The available models for estimating risks for death of fish, for example, should be used with the knowledge of their limitations, as they are made for blasting in open waters.