The compatibility between gynoecia of different penicillarian millets (Pennisetum glaucum and P. purpureum) and pollens from some other Poaceae was evaluated in order to determine whether different penicillarian pistils showed the same pistil-pollen interactions with a same non-penicillarian pollen and to determine whether compatibility was dependent on the genetic divergence or the degree of sympatric evolution of the matin" partners. Ten pearl millet fines (P glaucum subsp. glaucum), six wild pearl millet accessions (P glaucum subsp. monodii ) and one P purpureum accession were pollinated with five other Pennisetum species : P pedicellatum, P polystachyon, P schweinfurthii, P. squamulatum, P ramosum, and with three species from other genera : Cenchrus ciliaris, Panicum maximum and Zea mays. Each maie species was represented by a unique accession. Pollen grain germination on the stigmate and pollen tube growth in the gynoecia were monitored by means of fluorescence microscopy after aniline blue staining. Significant compatibility differences were observed between a given pollen and gynoecia from different P. glaucum accessions. But there was no evidence of compatibility differences between the three female taxonomie groupe. The eight pollen parents can be classified into three groupe according to their mean degree of compatibility with the different penicillarian gynoecia. P. ramosum, P. schweinfurthii and P. squamulatum showed a high compatibility : more than 50% of penicillarian gynoecia had pollen tubes at the micropyle, six hours after pollination. Zea mays, Cenchrus ciliaris and Panicum maximum showed a low compatibility : pollen tubes were arrested in the style. P. pedicellatum and P. polystachyon showed nil compatibility : few pollen grains germinated on the stigmate and very rare tubes reached the entry of the style, where they stopped. It must be noted that such a strong gametic barrier has been observed only with pollinator species sympatric to pearl mill