Functional neuroimaging studies of single word processing have demonstrated decreased activation in left inferior prefrontal cortex (LIPC) during repeated relative to initial semantic processing. This item-specific memory effect occurs under implicit test instructions and represents word-to-word semantic repetition priming. The present study was designed to examine the stimulus generality of LIPC function by measuring LIPC activation during repeated relative to initial semantic processing of words (word-to-word semantic repetition priming) and of pictures (picture-to-picture semantic repetition priming). For both words and pictures, activation was found to decrease during repeated semantic processing suggesting that the LIPC area is involved in semantic processing of stimuli regardless of perceptual form. Decreased LIPC activation was greater in extent for words than for pictures. The LIPC area may act as a semantic executive system that mediates on-line retrieval of semantic representations necessary for guiding task performance.