Purpose: The goal of this research was to examine whether phonological familiarity exerts different effects on novel word learning for familiar versus unfamiliar referents and whether successful word learning is associated with increased second-language experience. Method: Eighty-one adult native English speakers with various levels of Spanish knowledge learned phonologically familiar novel words (constructed using English sounds) or phonologically unfamiliar novel words (constructed using non-English and non-Spanish sounds) in association with either familiar or unfamiliar referents. Retention was tested via a forced-choice recognition task. A median-split procedure identified high-ability and low-ability word learners in each condition, and the two groups were compared on measures of second-language experience. Results: Findings suggest that the ability to accurately match newly learned novel names to their appropriate referents is facilitated by phonological familiarity only for familiar referents but not for unfamiliar referents. Moreover, more extensive second-language learning experience characterized superior learners primarily in one word-learning condition: in which phonologically unfamiliar novel words were paired with familiar referents. Conclusions: Together, these findings indicate that phonological familiarity facilitates novel word learning only for familiar referents and that experience with learning a second language may have a specific impact on novel vocabulary learning in adults. (Contains 3 tables and 1 figure.)