The widespread use of mobile phones and Wi‐Fi‐based communication devices makes exposure to radiofrequency electromagnetic fields (RF‐EMF) unavoidable. Previous experiments have revealed the tumor‐promoting effects of non‐ionizing RF‐EMF in adult carcinogen‐treated mice in utero. To extend these investigations, we tested whether these effects are due to the co‐carcinogenicity of RF‐EMF which would manifest as elevated DNA damage. Similar to previous experiments, pregnant mice were exposed to RF‐EMF (Universal Mobile Telecommunication System [UMTS] standard, approximately 1,960 MHz) from day 7 post‐conception (p.c.) at 0 (sham), 0.04, and 0.4 W/kg SAR. At day 14 p.c., the mice were injected with the carcinogen ethylnitrosourea (ENU, 40 mg/kg). At three time‐points specifically 24, 36, and 72 h later, the pregnant females were sacrificed and the fetuses (n = 24–57) were removed. A dye (cy3) specific for adenyl adducts was used to detect DNA damage by fluorescence microscopy in the brain, liver, and lung of each fetus. Compared to control (0 W/kg SAR), exposure to RF‐EMF had no effect on the formation of DNA adducts in the inspected tissues. We conclude that increased adenyl formation of DNA by RF‐EMF exposure is not a valid explanation for the previously reported tumor‐promoting effects of RF‐RMF. Our findings may help to gain a deeper insight into the biological effects of RF‐EMF exposure in the context of malignancy. © 2020 The Authors. Bioelectromagnetics published by Wiley Periodicals LLC on behalf of Bioelectromagnetics Society