Two experiments assessing the effects of altruistic models upon subsequent helping behaviors were conducted. The sites of the experiments were the parking lots of two large department stores located in either Princeton or Trenton, New Jersey. Shoppers served as the Ss. Ss in the model condition were exposed to a collaborator of E who, at certain fixed intervals, contributed money to the Salvation Army by throwing a nickel into the Army's kettle. Following the contribution, the subsequent number of donors who then contributed within the next 20-second (Experiment 1) or 30-second interval (Experiment 2) were tallied. Ss in the no-model condition were not exposed to E's donating collaborator, although they may have been exposed to other donors. The number of donors within the appropriate time intervals were tallied. One model and one no-model observational period occurred every minute. Results of both experiments strongly support the hypothesis that altruistic models will affect the subsequent aiding behaviors of the observers.