In 1980-1981, 209 imported measles cases were reported in the USA. These cases represent 1.3% of the total of 16,630 cases of measles reported to the Centers for Disease Control (CDC) [Atlanta, Georgia, USA] during that period. An average of 7 imported measles cases were reported each week. The travelers with imported measles were USA citizens and foreign nationals who arrived from 47 different countries throughout the world. Returning USA citizens have accounted for a rising proportion of imported measles cases. Approximately half (49.3%) of the imported cases were reported by 4 areas: California, New York Stae exclusive of New York City, New York City and Florida. Seven measles outbreaks occurring following importations during the 2-yr period were identified. In addition to 114 imported measles cases reported to the CDC in 1981, 437 measles cases were reported to be caused directly or indirectly by those importations. The actual number of import-associated cases may have been considerably higher. Imported measles and associated cases together accounted for at least 17% (551/3124) of reported measles cases in 1981.