The present study investigated the differences in attitudes and motivation between more effective and less effective learners studying at the first year of graduate university program. Based on this aim, first, the researcher developed the three-part 35-item attitude-motivation questionnaire of the present study based on the AMTB developed by Gardner (1985). Second, he selected 441 students (224 male & 217 female) studying at the first year of their graduate program at universities in East Azarbayjan province (Iran) as the participants of the study. Third, he administered the questionnaire of the study to the selected participants and asked them to complete it. Finally, he analyzed the data of the study in order to answer the mentioned research questions. The chi-square test was utilized to analyze the collected data of the study. The results of the study showed that there were significant differences between more effective and less effective learners' attitudes and motivation. Based on the results of the study, it was argued that, the EFL syllabus designers and teachers should help the learners to become aware of their attitudes, and motivational orientations. Furthermore, they should make an effort to tailor classroom materials and classroom teaching to the EFL learners' individual differences.