The current bilingual study investigated the processing of lexical ambiguity to test L1 influence on L2 processing. A primed lexical decision experiment was conducted in L2 (English) with high and less proficient German speakers. In the experiment, English-German interlingual homograph translations pairs like chef-boss (chef means boss in German) resulted in RT priming for the high proficiency group who had been contextually primed by watching a movie narrated in German prior to the experiment. The low proficiency group showed a similar result only when they had been previously exposed to the same movie narrated in English. The ERP data for the high proficiency group showed significant priming effects in the first half of the experiment, while priming only occurred for the low proficiency group in the second half of the experiment. Taken together, the results support the view that L1 influences L2 lexical processing. In particular, the data imply that L2 learners are not able to consciously suppress L1 influence.