The purpose of this study is to explore the existing effect of gloss conditions on reading comprehension and vocabulary understanding of learners in the context of English as a foreign language. The study composed of 72 male students aged between 19 and 21 years selected from Qassim University in Saudi Arabia. The participants were divided into four groups, namely; L1 Arabic gloss, L2 English gloss, a combination of L1 and L2, and the last group with no gloss. Results and findings of the study revealed a significant difference regarding the comprehension of the texts among the experimental groups when correlated with the control group. Additionally, there was no significant change noted regarding performance among the experimental groups. Another finding indicated that the learners had a preference of L1 and L2 gloss over L1 gloss and L2 gloss types, with 93.03% of them preferring to read glossed texts. Overall, these findings suggest that the gloss and no conditions were significantly distinct. This research results will be beneficial for future studies that are interested in developing reading comprehension of EFL learners.