The aim of this investigation has been to predict Viewing Comprehension through Aural and Picture Vocabulary Size among Iranian EFL Learners . To this end, 110 intermediate students were selected from two institutes of a city in Khorasan Razavi province, Iran. Pictorial vocabulary knowledge of learners was tested by Picture Vocabulary Size Test, Aural vocabulary knowledge was measured by Aural vocabulary size test and viewing comprehension was tested by a multiple-choice question test. All analyses were carried out using SPSS for Microsoft windows 22. Pearson product moment correlation analysis was run to analyze the relationship among viewing comprehension, picture vocabulary size and aural vocabulary . After the correlation analysis, we did step-wise multiple regression analysis to predict an outcome variable from two predictors . Interestingly, it was found that both picture and aural vocabulary size have a significant positive correlation with viewing comprehension. It was also proved that only aural vocabulary size can be considered as a significant predictor of EFL learners' viewing comprehension ability.
