Genetic monitoring of the environment is an important component in the analysis of the status of the biosystems. Its efficiency depends on the correct choice of (a) natural bioindicator species; (b) appropriate signs reflecting the state of the environment; and (c) appropriate statistical analysis. The assessment of genomes’ integrity plays the key role in the studies of mutagenicity in a polluted environment. We present a step-by-step recommendations for the analysis of the cytogenetic data and discuss the prospects of applying genetic tests for ecological monitoring, based on the example of analysis using crustacean species.