Since April 1997, CDC has received reports of outbreaks of cyclosporiasis in the United States and Canada (1,2). As of June 11, there have been 21 clusters of cases of cyclosporiasis reported from eight states (California, Florida, Maryland, Nebraska, Nevada, New York, Rhode Island, and Texas) and one province in Canada (Ontario). These clusters were associated with events (e.g., receptions, banquets, or time-place-related exposures [meals in the same restaurant on the same day]) that occurred during March 19-May 25 and comprise approximately 140 laboratory-confirmed and 370 clinically defined cases of cyclosporiasis. In addition, four laboratory-confirmed and approximately 220 clinically defined cases have been reported among persons who, during March 29-April 5, were on a cruise ship that departed from Florida. Approximately 70 laboratory-confirmed sporadic cases (i.e., cases not associated with events, the cruise, or recent overseas travel) have been reported in the United States and Canada. The most recent laboratory-confirmed sporadic case occurred in a person who had onset of symptoms on June 3.