This study assessed differences in response rates to a series of three-wave mail surveys when amiable or insistently worded postcards were the third wave of the mailing. Three studies were conducted; one with a sample of 600 health commissioners, one with a sample of 680 vascular nurses, and one with 600 elementary school secretaries. The combined response rates for the first and second wave mailings were 65.8%, 67.6%, and 62.4%, respectively. A total of 308 amiable and 308 insistent postcards were sent randomly to nonrespondents as the third wave mailing. Overall, there were 41 amiable and 52 insistent postcards returned, not significantly different by chi-square test. However, a separate chi-square test for one of the three studies, the nurses' study, did find a significant difference in favor of the insistently worded postcards.