With the advancement in technology and the emphasis on computer science education, there has been a strong push for more widespread programming instruction at K-12 and higher education levels. Existing research has mostly focused on students at the secondary and post-secondary levels. Not much research has involved students at the elementary school age, which has been considered a critical age to cultivate an interest in programming. The current study aimed to investigate the effects of a block-based programming interface (e.g., Hopscotch) on elementary school students' attitudes toward programming. In this study, eighteen elementary school students in 4th-5th grades participated in a programming curriculum for about seven weeks in the US. A survey on attitudes toward programming was distributed before and after the curriculum, to explore the change in attitudes toward programming. Students' views about the block-based programming interface (e.g., Hopscotch) were also examined after the curricular activities. Students' activities in lessons and artifacts from the culminating project were observed. The findings indicated that elementary school students had positive views about programming in the block-based programming interface. Also, the block-based programming activities contributed to more positive attitudes toward programming. Implications and limitations of the study were discussed.