This study investigated the production of Mandarin disyllabic tones by Korean speakers. We focused on disyllabic tones since it is disyllabic words that dominate the vocabulary in modern Mandarin. In particular, we examined the tonal production in Mandarin by Korean speakers, which is somewhat understudied in the previous literature. In our study, there were 25 Korean learners of Mandarin, who were requested to produce 80 Mandarin disyllabic words with all tonal combinations (except for the neutral tone). The overall results showed a level of difficulty: Tone 2 = Tone 3 > Tone 1 = Tone 4. Most errors in the first syllable were found for Tone 2 and Tone 3 when followed by Tone 1 or Tone 4 (both start with a high pitch). In the second syllable, error patterns among those tones were not significantly different. Other errors for specific tones were also analyzed. The findings are discussed from the perspectives of phonetic representations of lexical tones as well as effects of native phonology in the first language.