In this study, all levels of microwave radiation around the 32 Global System for Mobile (GSM) masts/towers in operation at different locations in Ile-Ife city as at July 2012 were assessed. Using an electrosmogmeter, the instantaneous electric field E, average maximum of electric field E , instantaneous power density (d), and max,av average maximum power density d , of microwave radiation were measured around these masts. Three max,av hundred and three (303) sampling points were chosen, with a minimum of eight measuring points (with their Global Positional System-GPS coordinates recorded) around each of the masts. Contour maps of the magnitude of these variables at Ile-Ife were thereafter produced using ARCGIS 10.1 software. Furthermore, the same four radiation parameters were measured in some popular brands of cell phones under various operating and signal receptivity conditions. The results showed that in Ile-Ife, E ranged from 57-480 max,av 2 mV/m, E ranged from 85-566 mV/m, d ranged from 25-448 mW/m , and d ranged from 527-2,106 max,av 2 mW/m. The lowest value was at Adegoke area with E ranging from 9-281 mV/m, E ranging from 85-max,av 2 2 285mV/m, d ranging from 0.1-217 mW/m , and d ranging from 0.2-225 mW/m. At the OAU Teaching max,av 2 Hospital, E ranged from 145-708 mV/m, E from 173-798 mV/m, d from 65-1,361 mW/m and d max,av max,av 2 from 96-1,811 mW/m. For the cell phones, E ranged from 0.9-199 mV/m, E ranged from 5,700-max,av 2 2 20,000 mV/m, d ranged from 0.1-81 mW/m and d ranged from 86-989 mW/m. Phone brand, signal max,av strength, and phone activity (standby, connecting, receiving, calling, or texting) significantly affected the radiation outputs from the cell phones. Though radiation output values obtained in this survey were in compliance with guideline values set by the ICNIRP, which is the standard adopted by the Federal Ministry of 2 Environment for Nigeria, they exceed, at several locations, the precautionary limits of 1,000 mW/m suggested in the more realistic and widely acclaimed Bioinitiative Report.