This study aimed at determining how the effect of Wi-Fi 4G electromagnetic wave radiation exposure to the volume of testes, epididymis and sperm quality in male Wistar rats (Rattus norvegicus). This research was conducted at Laboratory of Medical Biology of Sriwijaya University with Pretest-Postest Control Group Design. A total of 28 males Wistar rats were divided into 2 groups randomly: control group and treatment group. Treatment group was divided into 3 groups, each group was exposed 8, 16, 24 hours per day, daily radiation for 48 days. After the rats were terminated, the surgery was performed by taking secretions from the cauda epididymis.The data were analyzed by One Way Anova test. After being exposed to radiation of 4G Wi-Fi electromagnetic waves, there was significantly different mean, decreasing testicular volume, epididymis and sperm morphology value (p = 0,000) with alpha value 0.05 (p <α) in comparison with the control group. It was concluded that the exposure of 4G Wi-Fi electromagnetic radiation could decrease the volume of epididymis and sperm morphology on male Wistar rats, especially, on 24 hours exposure. Keywords: epididymis, 4G Wi-Fi, sperm morphology.