With the advent of mobile technology, teaching and learning have been more effective with the help of smartphone education applications. This study investigates the effects of vocabulary learning using the smartphone education applications on Korean elementary school learners’ English vocabulary learning and attitudes. A total of fifty-seven elementary school students in the 5th grade participated in the study and were randomly divided into an experimental and a control group. The results of the study manifested that both the experimental and control group showed an increase in the comprehension and production score from pre- to post-tests. The effects of the long-term vocabulary learning, however, were not found to be statistically significant. The average score in the delayed test for both groups slightly increased, which indicated that the treatment was beneficial for learners’ long-term memory enhancement. In the affective domain, interests and confidence ratings were significant for the upper-level experimental and lower-level control group. The results of the survey questionnaire showed that the vocabulary learning using direct examples and pictures for both groups was helpful to improve learners’ lexical competence.