Nowadays, translation into a foreign language (L2) has become a widespread practice. However, this type of translation is known to be more challenging than translation into the mother tongue (L1). This suggests that translation-oriented foreign language teaching should be geared towards equipping learners with the necessary knowledge, skills and abilities for performing L2 translation. One such aspect is creating a meaningful link between L1 and L2 equivalents and ensuring better retention, recall and retrieval of L2 vocabulary in response to L1 equivalents. The aim of this study was to test whether using L1 to L2 learning in combination with the ‘notice-the-gap’ principle in teaching vocabulary to trainee translators can facilitate the achievement of this result. The participants were thirty 3rd-year full-time translation students enrolled on a 5-year translation training programme at the Linguistics University of Nizhny Novgorod, Russia. The proposed approach was used in teaching vocabulary to an experimental group of students whose results before and after the treatment were compared with those of a control group using statistical tests. The results testify to the effectiveness of the proposed approach. The experimental group demonstrated a significant reduction in the performance time in L2 translation accompanied by improved accuracy of L2 use, i.e., retrieval of appropriate and adequate L2 vocabulary in response to their L1 equivalents. The findings have significant implications for translation-oriented foreign language teaching in terms of highlighting the importance of strengthening the L1 to L2 lexical link. On a practical level, the study provides specific recommendations and a learning procedure for achieving this aim.