Environmental exposure to nonylphenol (NP) can adversely affect human and wildlife health. A systematic review was conducted to evaluate the relationship between environmental NP exposure and cancer progression risk. Literature surveys were conducted within several international databases using appropriate keywords. A comprehensive search yielded 58 eligible studies involving a wide range of adverse effects, exposure assessment methods, study designs, and experimental models. Most studies reported that NP strongly induced breast cancer progression in intended experiments. Positive associations between NP exposure and ovarian, uterine, pituitary, and testicular cancers were also reported. Although some studies reported no relation between environmental NP exposure and tumour and/or cancer progression, NP (a known endocrine disrupting chemical) induced action mechanisms in multiple experimental models and may interfere with/hyper-activate oestrogen signalling. Secretion of oestrogen and development of reproductive tissues like breasts, uteruses, and ovaries showed strong associations with possible neoplasia (i.e., uncontrolled development of tumours and/or malignant cancers). Findings of this study are important for informing policymakers to pass legislation limiting the use of environmental contaminants such as NP before all adverse effects of exposure have been determined.Copyright © 2020 Elsevier Inc. All rights reserved.