Modified live vaccine is used by sixty-seven percent of feedlot operators in their arrival-processing program, and seventy-two percent of feedlot operators use modified live vaccine for re-vaccination. Sixty-nine percent of respondents indicated they were satisfied with the preconditioned calves they purchased. Forty-four percent of respondents who indicated they were dissatisfied with purchased preconditioned calves were dissatisfied because of illness. Thirty-six percent of feedlot operators indicated they would like to see Pasteurella vaccination required in the Iowa preconditioning program. Feedlot operators were asked to rate the importance of the requirements in the preconditiong program using a scale of one to five, with one meaning not important and five very important. The operators rated most of the requirements as four or five except for weaning ration, castration date, and dehorning date. This survey indicates that preconditioned calves are well accepted by feedlot operators in Iowa, and that the preconditioning certificate should accompany the calves through the marketing process.The Iowa Preconditioning program is the oldest sponsored program of its type in North America. The objectives of this project were to determine the attitudes and experiences of feedlot operators about the Iowa preconditioning program. A survey was developed to examine these attitudes and experiences. The survey was mailed to four hundred fifty feedlot operators in Iowa. There was a thirteen percent response rate. Sixty-one percent of the respondents operate feedlots with less than one thousand head one time capacity. Fifty-three percent of respondents had purchased Iowa preconditioned calves in the last year. More than fifty percent of respondents want information on what vaccinations were given to the replacement calves prior to arrival in the feedlot. Feedlot operators feel it is important to have information on vaccination history but only forty-five percent use the information to make decisions on the arrival-processing program for new replacements. Eighty-four percent of the respondents indicated respiratory disease was the health problem most often observed the first month replacements are in the feedlot, but only fifty-one percent of respondents indicated respiratory disease was a health problem the first month Iowa preconditioned calves are in the feedlot.