It is generally agreed that healthcare workers are ideally positioned to recognize and diagnose cases of elder abuse. However, little is known about their knowledge and understanding of this issue. The objective of this study was to assess and compare the perceptions of different groups of healthcare workers toward elder abuse in Japan, using the Knowledge-Attitude-Behavior (KAB) model. Home-visit nurses, medical doctors, care managers, care workers, public health nurses, and social workers, with experience of dealing with elder abuse received self-administered questionnaire surveys that inquired regarding demographics, knowledge, attitudes, and behaviors regarding elder abuse. A total of 311 healthcare workers participated in this survey. To compare the differences among the groups, a one-way analysis of variance with a post-hoc Tukey's test, and a Kruskal-Wallis with post-hoc Steel-Dwass tests were used in accordance with data normality. Multiple linear regression analysis was conducted to explore variables that predicted the healthcare workers' perceptions, and covariance structure analysis was used to examine whether the KAB model can accurately predict healthcare workers' perceptions. Multiple comparisons showed significant differences in knowledge, attitudes, and behaviors regarding elder abuse among the abovementioned six groups. Age, sex, and years of work related to the care of elderly were extracted as significant determinants of healthcare workers' perceptions of elder abuse. The examination of the KAB model with covariance structure analysis yielded a model with strong goodness-of-fit. These findings emphasize the need to take effective measures to improve their perceptions as well as review the role of each healthcare worker so that they can be more concerned with and involved in the safeguarding of the elderly. Given the strong goodness-of-fit demonstrated by the KAB model, education of healthcare workers on both the knowledge of, and attitudes toward, elder abuse may help in improving healthcare workers' behavior in dealing with elder abuse.