In this paper, we examine some of the factors that might influence the accessing of meanings of written and spoken L3 words. We tested learners of L3 French who had Finnish as their L1 and were highly competent in L2 English. They were presented with L3 French words in written and spoken form, and were asked to give a possible translation for the target word in L1 and to rate their level of confidence in the meaning given. Because of their instructional learning background, we expected orthographic forms to be more familiar than phonological ones. This hypothesis was confirmed. The meanings of the L3 words presented were accessed more easily and more accurately in the orthographic than in the phonological modality, although this asymmetry decreased with a higher level of proficiency. The confidence ratings were negatively affected by a similarity to L2 words. General implications for L3 lexical knowledge are discussed.