This comparative analysis of dated HA and NA sequences from influenza A(H3N2) viruses from 4 geographical regions of the world (New York, Western Australia, New Zealand and Hong Kong) attempts to elucidate more clearly the behavior of influenza A(H3N2). This study contributes an additional 10 years of influenza A(H3N2) HA and NA sequences, from Hong Kong, to the publicly available sequence database (GenBank), which should aid other researchers investigating an underlying basis for influenza A(H3N2) seasonality.