between phospholearomaticity and pyramidality at phosphorus. It has been found that both the highly pyramidal 1-cyanophosphole 1 (sigma(CPC angles) = 290 degrees), and the much less pyramidal 1-alkoxyphosphole 6 (sigma(CPC angles) = 310 degrees) have a low Bird aromaticity index (27 for both molecules), when compared to 1-benzylphosphole (sigma(CPC angles) = 303 degrees, BI = 35.5). This low aromaticity