Chromosome countings have been rnade on lhe endosperm of Coffea using the same technique of acetic oreein already referred to in previous work of the author. Endosperm from the varieties typica and semperflorens (2n = 44) and monosomic plants (2n = 43) of C. arabica as well as of other species as C. canephora (2n = 22), C. dewevrei (2n = 22), C. eugenioides x C. kapakata (2n = 22) and duplicated C. eugenioides (2n = 44) were studied. Gametic number of chromosomes are discussed leading in some cases to the conclusion that gametes with missing chromosomes and gametes with supernumerary chromosomes were functional. Endomitosis was observed in all material studied. Endosperm tissue is constituted, therefore, by polysomatic cells (6x, 12x) in addition to the monosomatic ones (3x) initially formed through fertilization. The possible relation of endomitosis and embryo development is also discussed. The great number of photomicrographies obtained indicates once more that coffee endosperm is a favourable material for cytological investigations.