In the spring of 1957, populations of the alfalfa weevil, Hypera postica (Gyllenhal), reached serious economic proportions in North Carolina. Four field tests planted with a total of 294 varieties and experimental strains of alfalfa were used in a study to determine whether varieties and strains differed in their reactions to the alfalfa weevil. All plots were scored in the field and in the laboratory for weevil damage. Data on larval infestation by the weevil and plant height also were taken. Tolerance ratings were based on foliage damage relative to larval infestation and preference ratings were based on larval infestation relative to infestation of a standard variety, Atlantic, in the same test. Severe damage occurred in all tests, but differences between plots were apparent. Analyses of variance generally indicated small but significant differences among alfalfa entries for field damage scores, number of larvae per 10 stems, and tolerance ratings, It was not possible, however, to ascertain whether differences in the degree of damage were due to inherent differences in susceptibility per se or to growth characteristics which may have affected the activity of the weevil. In either event, none of the strains or varieties studied appeared sufficiently resistant to offer a satisfactory control of the weevil.