Background & objectives: Cell phone microwave (MW) is one of the most harmful physical agents in modern society. This study was designed to determine the effects of exposure to cell phone microwaves on mice sperm morphologic indices. Methods: Animals were divided into two groups including: Microwave (MW) (n=6; exposed to 950-MHz cell phone MW with 5 W output power density and 200 KHz modulation during 10 days for 8 hrs/day) and Control (C) (n=6; similar situation; not exposed to MW) groups. After exposure, all mice were anesthetized; their testis epididymis tails were extracted and put in mix culture of Hams F10 and 10% human albumin. Paraffin blocks with sections of 5μ m thicknesses were prepared and testis tissue indices were determined. The average obtained by three repeats within a group was reported as Mean± S. D and significant level considered P<0. 05. Data were analyzed by one-way ANOVA test. Results: There were significant differences in total sperm motility (MW: 60. 70± 0. 96; Control: 72. 4± 1. 02), the percentage of normal sperm morphology (MW: 45. 30± 50. 58; Control: 73. 35± 1. 60), the percentage of sperm viability (MW: 58. 68± 1. 44; Control: 74. 36± 1. 65), and tubules inner diameter (MW: 97. 11± 1. 79; Control: 66. 82± 1. 02) (p<0. 05); while, no significant differences were observed in sperm count per million (MW: 4. 11± 1. 11; Control: 4. 51± 0. 09) and tubules outer diameter (MW: 160. 27± 1. 95; Control: 161. 89± 1. 33). Conclusions: 950-MHz cell phone MW exposure led to decreased total sperm motility, diminished percentage of normal sperm morphology, reduced percentage of sperm viability (which is expected to increase the possibility of male factor infertility with varying degrees over time), and increased tubules inner diameter (which indicates differentiation and cell death in different classes of germinal cells).