This study attempted to examine the influence of a decrease in translation on the number of words read, reading comprehension, and reading rate in an extensive reading (ER) program. The participants were 70 first-year university students who experienced ER both in and outside the classroom for 15 weeks. The results of regression analyses confirmed that a decrease in translation and grammar analyses statistically significantly affected all three. A further investigation found that a decrease in translation overall as well as in grammar analyses made a difference in the means of the number of words read and the post-test scores. Moreover, a decrease in translation at the word level was statistically significant on reading comprehension, and so was a decrease in translation at the sentence level on the amount of reading. The results were discussed referring to automaticity together with the prior educational experience and mentality of typical Japanese students.