In this paper chromosome counts for 90 collections representing 67 native Hawaiian angiosperm species and eight hybrids in 22 families are presented and discussed. Included are the first records for 26 species, two subspecific taxa, eight natural hybrids, and the endemic genus Pteralyxia (Apocynaceae). In four families Hawaiian representatives have been investigated cytologically for the first time. For three species the investigations are the first on Hawaiian material. Seven counts differ from earlier reports in the literature. Implications of the results are discussed in the context of autochthonous chromosomal evolution and of colonization events for the Hawaiian Islands.