With the protracted and ever-increasing higher demand for electricity than the relatively constant supply in Nigeria, the provision of electricity has been epileptic in nature. This has led to the private and commercial generation of power for use through backup generators. The noise emanating from the operation of generators in the country has been of great concern as it is presently a social menace coupled with a negative impact on public health. The dearth of literature on generator-induced noise has ignited this study. The noise level of 96 household gasoline-fueled generators selected at random was measured using a noise meter. At 10 min interval for 1 h and a height of 1.5 m above the ground, the noise levels of the generators were measured. Data of the age, operating hours, efficiency, installed and operating capacity of the generators were also garnered. The work was carried out at Sango-Ota, Ogun State, Nigeria. The characteristics of the investigated generators were; age of 1 – 144 months, efficiency of 9.2% – 88%, operating hours of 1 – 15 h, installed capacity of 650 VA – 4200 VA, and estimated load of 250 W – 2300 W. Noise level range of 37.3 dB – 100.4 dB with an average of 64.0 dB ± 1.3% was obtained. In addition, the World Health Organization (WHO) recommendations of 45 dB (night) and 55 dB (day) for residential areas were found to be moderately lower than the average noise level measured in this work. Furthermore, only 15 (15.6%) and 2 (2.1%) generators out of 96 were noticed to comply with the WHO threshold values of 45 dB and 55 dB, respectively. These findings revealed the potential adverse effects of noise stemming from the operation of generators on the public wellbeing coupled with the associated health problems. The generators’ efficiency was noticed to have the most impact on the noise level with 26 (27.1%) of them having ⩾60% efficiency. This showed the inefficient use of generators as most of them with high installed capacity were used to power small electrical loads. Improving electricity supply, utilizing renewable energy, and adopting efficient noise control technologies were recommended as measures to reduce noise level via generators.