Compounding, the concatenation of words (e.g. dishwasher), is an important mechanism across many languages. This study investigated whether access of initial compound constituents occurs immediately or, alternatively, whether it is delayed until the last constituent (i.e. the head). Electroencephalogram was measured as participants listened to German two-constituent compounds. Both the initial as well as the following head constituent could consist of either a word or nonword, resulting in four experimental conditions. Results showed a larger N400 for initial nonword constituents, suggesting that lexical access was attempted before the head. Thus, this study provides direct evidence that lexical access of transparent compound constituents in German occurs immediately, and is not delayed until the compound head is encountered.