Biocides (disinfectants and antiseptics) are commonly used to prevent disease and reduce the number of microorganisms in medical, industrial, and food production settings. Biocide efficacy tests (BET) are conducted to determine the ability of a biocide to effectively control or destroy microorganisms. Various methods have been developed to determine the effectiveness of biocidal products. Quantitative and qualitative suspension tests are used to measure the antimicrobial activity of biocides. Additionally, various testing methodologies are available, including phenol coefficient testing, carrier tests, and practical tests. Standards such as European Standards (EN) 14348 and EN 14563 are employed to ascertain the efficacy of biocides, with tests conducted under specified temperatures and contact times and evaluated through the measurement of logarithmic reduction in microbial populations. The assessment of the efficacy of biocides is of significant importance in many fields, including healthcare, food safety, and agriculture. These tests are standardized tests that are required by regulatory agencies when assessing the effects of biocides on human health and the environment. Research and development studies on BET are of great importance. Each new study in this field provides a significant opportunity to enhance the accuracy and applicability of the tests. Consequently, as the necessity of BET is increasingly acknowledged, the demand for research and development activities in this field is also growing. This review provides comprehensive information on the types, application areas, standards, and significance of BET.