A fundamental property of visual attention is to select targets from interfering distractors. However, attention can also facilitate the detectability of near-threshold items presented in isolation. The extent to which these two perceptually challenging conditions are resolved by the same neural mechanisms is not well known. In the present event-related fMRI experiment, subjects performed a letter identification task under two perceptually challenging conditions; when the luminance contrast of a target letter was reduced (perceptual visibility manipulation) and when the target letter was flanked by distractors (perceptual interference manipulation). Perceptual interference recruited the right parietal and mid-lateral frontal cortex, while perceptual visibility activated these regions bilaterally. The overlap of activated areas between the two perceptual manipulations suggests that a single parieto-frontal network is summoned under both perceptual visibility and interference conditions.