An experiment was designed to test if the contamination of intensely used beaches by solid wastes could be correlated to the presence of users. Profiles perpendicular to the water line were marked on Boa Viagem Beach, Recife City, Pernambuco, Brazilian Northeast. The solid waste items collected within these profiles at days of high user frequency revealed that some items might be used as flags for the presence (and contribution to the contamination) of users on the beach. Such items especially abundant were plastic cups and drinking straws. The contamination of the beach has the same qualitative character at all sites at all times. However, the amount of flag items changes according to the more intense use of the beach, especially during summer weekends and sociocultural events, when use reaches its maximum intensity.