Little is known about language development after late‐to‐moderate premature birth, the most significant part of prematurity worldwide. We examined minimal‐pair word‐learning skills in 18 eighteen‐month‐old healthy full‐term (mean gestational age [GA] at birth = 39.6 weeks; 7 males; 100% Caucasian) and 18 healthy late‐to‐moderate preterm infants (mean GA at birth 33.7 weeks; 11 males; 100% Caucasian). Data were collected in the local urban area of Barcelona city from May 2015 to August 2016. Toddlers first associated two pseudo‐words, forming a minimal pair based on a voice onset time distinction of the initial consonant, with two unfamiliar objects during a habituation phase. A visual choice test assessed their recognition of the two novel word‐object associations and some familiar word‐object pairs. While full‐terms successfully mapped the similar sounding pair of novel words (d = 1.57), preterms could not (d = 0.17). These results suggest that late to moderate preterm birth can hinder basic associative learning mechanisms relying on fine temporal speech features.