The current study aims at investigating the effect of a suggested CALL program on developing EFL learners' mechanics of writing in English. An unbiased simple random sample of eighty fourth-year students (2006/2007) of the English Department at the Faculty of Education in Kafr El-Sheikh has been chosen to carry out the experiment. Forty students have been assigned to the experimental group to study mechanics of writing via the CALL program. An equal number of students has been assigned to the control group to study the same content as usual. Material and tools, designed by the researcher, have been used either to collect the data or to carry out the experiment of this piece of research: a pilot study; an achievement test; the CALL program; a lecturer's guide; a students' guide and a questionnaire. The experiment has taken ten weeks--including the pretest and posttest administrations. Afterwards, the researcher has used the One-Way ANOVA and the t-test in order to statistically analyze the obtained data. Findings refer to the fact that the suggested CALL program does develop EFL college learners' punctuation marks, capitalization and spelling (the three investigated components of writing mechanics). Also includes 13 appendixes. (Contains 22 tables and 8 figures.) [Master's Thesis, Kafr El-Sheikh University.]