This paper attempts to investigate the effect of using cell phone dictionaries on improving male and female Iranian high school EFL learners’ spelling. To this end, ninety participants were randomly selected from Dinodanesh and Etrat high schools in Lordegan city, and they were given a spelling pretest based on their course book. Then sixty subjects whose scores were within the range of one standard deviation above and below the mean were selected as homogeneous and divided into experimental and control groups. Using cell phone dictionaries was conducted in eight class session, during which experimental group received training with cell phone dictionaries while the control group only received training without any cell phone dictionaries. The data were collected via a pretest and a posttest. The analysis of the test scores using t-test revealed that the experimental group did statistically better in the test. The results revealed that using cell phone dictionary had positive effect on improving EFL learners’ spelling. At the end, a two-way ANOVA was run to compare the two groups plus the effect of gender on such performance. The results indicated that treatment have an effect on the improving of both male and female EFL learners’ spelling.