This study investigated relationships among intelligibility, comprehensibility, and accentedness in the speech of L2 learners of Spanish who completed a prompted response speaking task. Thirty native Spanish listeners from Spain were recruited through Amazon Mechanical Turk to transcribe and rate extracted utterances, which were also coded for grammatical and phonemic errors, and speaking rate. Descriptively, although most utterances were intelligible, their comprehensibility and accentedness varied substantially. Mixed-effects modeling showed that comprehensibility was significantly associated with intelligibility whereas accentedness was not. Additionally, phonemic and grammatical errors were significant predictors of intelligibility and comprehensibility, but only phonemic errors were significantly related to accentedness. Overall, phonemic errors displayed a stronger negative association with the listener-based dimensions than grammatical errors. These findings suggest that English-speaking learners of Spanish are not as uniformly intelligible and comprehensible as FL instructors might believe and shed light on relationships among speech constructs in an L2 other than English.