As metabolites of phthalate esters (PAEs), monophthalate esters (mPAEs) can enter the human body through dietary intake, dermal contact, and other routes. They have been widely detected in human blood, urine, and other body fluids and tissues. Due to their teratogenic, carcinogenic, and mutagenic effects, as well as reproductive, developmental, and embryonic toxicity, mPAEs can disrupt endocrine homeostasis, thereby posing significant risks to human health. This article summarizes the sources, formation mechanisms, structural characteristics, toxicity, and quantitative analysis of mPAEs, aiming to provide a theoretical reference for further research on mPAEs.