The present study intended to investigate the possible difference between EAP and EFL learners' beliefs concerning learning and teaching of language components, namely, vocabulary, pronunciation and grammar. Furthermore, this study examined the association between EAP and EFL learners' beliefs and their language components' development. To this end, 231 undergraduate EAP (117) and EFL (114) learners at Ferdowsi University took part in the study by completing a five-point Likert scale questionnaire adapted from Simon and Taverniers (2011). The face and content validity of the questionnaire was confirmed by the experts' judgment and factor analysis. Moreover using Cronbach alpha coefficient the questionnaire was found acceptably reliable (a = 0.88). Furthermore, for language components' development, the EAP learners' scores in English course and EFL learners' average scores in their Basic English courses were taken into account. The results of an Independent Samples t-test revealed that there existed a statistically significant difference between EAP and EFL learners' beliefs on learning and teaching language components. Furthermore, the results of Pearson correlation coefficients indicated a statistically significant positive association between EFL learners' beliefs and their language components' development, however no statistically significant correlation was found between EAP learners' beliefs and their language components' development.