Antibiotic resistance genes (ARGs) in the water environment are a growing concern. The use of antibiotics can accelerate the development of ARGs and bacteria that pose health risks to humans and animals. ARGs have been found in various water environments, including hospital and animal production wastewaters, sewage, wastewater treatment plants, surface water, groundwater, and even drinking water. This review summarizes recent information on the types, distributions, and horizontal transfer of ARGs in aquatic environments, as well as molecular methods used to detect environmental ARGs, such as specific and multiplex PCR, real-time PCR, DNA sequencing, and hybridization-based techniques. Antibiotics are widely used in human and veterinary medicine and agriculture, leading to their excretion into the environment. This has raised concerns about the potential impact of antibiotic residues in aquatic environments. Antibiotics can be detected in surface water, except in pristine mountain areas. Some antibiotics can also be found in groundwater as deep as 10 meters. In addition to chemical pollution, the use of antibiotics may accelerate the development of ARGs and bacteria that pose health risks to humans and animals. These bacteria can be transmitted to humans through direct or indirect contact. There is growing evidence that clinical resistance is closely associated with environmental ARGs and bacteria. Therefore, research should include nonpathogenic or environmental microorganisms. Although there are many publications on the occurrence of ARGs in different water environments, few reviews have been conducted. This paper provides an overview of the latest information available in the literature on the types, distributions, and horizontal transfer of ARGs in various aquatic environments, as well as the molecular methods used to detect environmental ARGs.Antibiotic resistance genes (ARGs) in the water environment are a growing concern. The use of antibiotics can accelerate the development of ARGs and bacteria that pose health risks to humans and animals. ARGs have been found in various water environments, including hospital and animal production wastewaters, sewage, wastewater treatment plants, surface water, groundwater, and even drinking water. This review summarizes recent information on the types, distributions, and horizontal transfer of ARGs in aquatic environments, as well as molecular methods used to detect environmental ARGs, such as specific and multiplex PCR, real-time PCR, DNA sequencing, and hybridization-based techniques. Antibiotics are widely used in human and veterinary medicine and agriculture, leading to their excretion into the environment. This has raised concerns about the potential impact of antibiotic residues in aquatic environments. Antibiotics can be detected in surface water, except in pristine mountain areas. Some antibiotics can also be found in groundwater as deep as 10 meters. In addition to chemical pollution, the use of antibiotics may accelerate the development of ARGs and bacteria that pose health risks to humans and animals. These bacteria can be transmitted to humans through direct or indirect contact. There is growing evidence that clinical resistance is closely associated with environmental ARGs and bacteria. Therefore, research should include nonpathogenic or environmental microorganisms. Although there are many publications on the occurrence of ARGs in different water environments, few reviews have been conducted. This paper provides an overview of the latest information available in the literature on the types, distributions, and horizontal transfer of ARGs in various aquatic environments, as well as the molecular methods used to detect environmental ARGs.