This study examined the asymmetrical language switching cost in a word reading task (Experiment 1) and in a categorization task (Experiment 2 and 3). In Experiment 1, Spanish-English bilinguals named words in first language (L1) and second language (L2) in a switching paradigm. They were slower to switch from their weaker L2 to their more dominant L1 than from L1 to L2. In Experiment 2 and 3, high vs. low English proficiency bilinguals decided whether a word visually presented in their L1 or L2 referred to an animate or to an inanimate entity. In this case, bilinguals did not show asymmetrical cost when they switched between languages. These results suggest that inhibitory processes in bilingual processing as indexed by the asymmetrical language switching cost are only observed when L1 and L2 lexical representations compete for selection (e.g. word naming task). In addition, L2 proficiency did not influence the absence of asymmetrical switching cost. (Contains 2 tables and 4 figures.)