Ageism in nursing is difficult to identify, prevent and combat. Using a mixed-method approach in two exploratory cross-sectional studies (N = 512), we brought support for a proposed conceptual difference between ageism toward older adults and ageism toward older patients which may facilitate the identification of ageism in healthcare settings. We also investigated whether nurses' moral sensitivity could buffer the negative effect of socio-cognitive factors on ageism against older patients. Our findings supported our assumption, suggesting that fostering nurses' moral sensitivity could be a promising new avenue to prevent and combat ageism in nurses, together with comprehensive gerontological education meant to decrease stereotyping and help nurses fulfill their roles of moral advocates against older patient discrimination.