Previous research has repeatedly revealed evidence for morpho-orthographic priming effects in suffixed words. However, evidence for the morphological chunking of prefixed words is sparse and ambiguous. The goal of the present study was to directly contrast the processing of prefixed and suffixed pseudowords within the same experiment. We carried out a masked primed lexical decision experiment, in which the same target (AMOUR [LOVE]) was preceded by a prefixed (préamour [prelove]), a nonprefixed (brosamour [broslove]), a suffixed (amouresse [lovedom]), and a nonsuffixed (amourugne [lovedel]) prime. The results revealed significant priming across all four conditions. Moreover, priming was modulated by individual differences in reading proficiency. High-proficiency readers showed evidence for embedded stem priming effects, independent of whether stems occurred in combination with a real affix or a nonaffix. This finding is of relevance to recent morphological processing theories, suggesting that embedded stems represent salient activation units during the reading of complex pseudowords.