The present study examined a hypothesized relationship between the following variables: intrinsic and extrinsic motivation as described by Self-Determination Theory (Deci & Ryan, 1985), integrative and instrumental orientation (Gardner & Lambert, 1972), attitudes toward pronunciation, and accent in English-speaking late learners of Japanese. Data collection occurred in two steps: First, English-speaking participants completed three questionnaires designed to measure their motivation and attitudes toward pronunciation; they then provided speech samples in Japanese. Native speakers of Japanese then rated these speech samples holistically on a scale of 1 to 5, with 1 indicating a strong foreign accent, and 5 indicating a native accent. Scores on the questionnaires were then correlated with the accent ratings. None of the English-speaking participants were judged as native or near-native speakers of Japanese. However, results demonstrated a significant positive correlation between ratings of accent and two variables: Intrinsic Motivation Toward Accomplishment and attitudes toward pronunciation. The statistical analysis also revealed a positive correlation between integrative and instrumental orientation and extrinsic motivation, suggesting a relationship between measures of orientation and extrinsic motivation as well. These results highlight the importance of including Self-Determination Theory in the area of second/foreign language acquisition research, as well as clarifying the role of motivation and attitudes toward pronunciation in the present context of late learners of Japanese.