Childhood stress affects both individuals throughout their lives and also their children. The mechanism of this intergenerational transmission of stress has been suggested to be epigenetic. Whilst evidence for pre-conception stress induced inter- and transgenerational epigenetic changes in rodents, indicative of some form of inheritance, a mechanism in humans has not been established. Only gametes can transmit genetic information across generations. Precise mechanisms for transmission require investigation, specifically in human gametes. The aim of this study is to investigate DNA methylation in sperm DNA in relation to early-life stress exposures of men. Sixty-four men recruited from Flinders Fertility clinic (mean age=35.6, stdev=5.2) completed in-depth psychological questionnaires including childhood stress (CTQ), and proximal measures for stress (Stress Overload Scale), distress (Depression, Anxiety, and Stress Scale), diet (Primescreen), exercise (GPAQ), and drug use (DAST). Excess sperm from the in-vitro fertilization (IVF) treatment underwent swim-up and was pelleted, snap-frozen, and transferred to -80C storage. DNA was extracted from the sperm pellets, and DNA methylation measured with the Infinium MethylationEpic BeadChip (Illumina). Sperm DNA methylation age will be calculated based on most recent sperm-specific clocks. We will determine if there is evidence for elevated sperm DNA methylation age in those exposed to greater childhood maltreatment. Differential methylation analyses will identify loci associated with increased childhood trauma. Covariates include age, body mass index, and sperm parameters. Attenuation of effects by proximal psychological and lifestyle measures will be investigated. This study is the largest to date to explore the relationship between childhood maltreatment and sperm epigenetics, and the first to undertake such in-depth confounder analyses. Expected outcomes include establishing a critical evidence-based foundation and resource for future research into epigenetic transmission. This should provide significant advancement of knowledge, and potential benefit to all Australians, especially children born into families with a history of trauma.