To date, little attention has been paid to the impact of immersion programs on learning interests in a second language (L2). The main purpose of this study was to investigate the effects of two types of Hakka-Chinese bilingual programs (immersion vs. non-immersion) on L2 learning interests. Four kindergarten teachers (two in each program) consented to rate a total of 114 kindergarteners aged five years at the beginning and the end of the semester. By conducting confirmatory factor analysis, paired t-tests, and ANCOVA, results showed: (1) Kindergarteners' learning interest in immersion programs could be differentiated into situational interest and individual interest, (2) The Hakka immersion and non-immersion programs both had positive effects on learning interest and (3) Both learning interests of kindergarteners in the immersion program were found to be inferior to that of kindergarteners in the non-immersion program when the initial differences in learning interests in these two programs were controlled. The results imply that the quality of a bilingual program is more important for cultivating an interest in second language learning than the percentage of time traditionally spent to differentiate between immersion and non-immersion programs (i.e. whether approximately 50% of the curriculum was used to teach a second language).