Recent evidence suggests that avoiding waste may be a prominent motive to save in hoarding disorder. Such beliefs are reminiscent of scrupulosity obsessions in OCD. This paper reports on three studies examining scrupulosity-like beliefs in hoarding and the development and validation of a measure of material scrupulosity.Study one examined the reliability and validity of a measure of material scrupulosity (MOMS) and its relationship to hoarding in a college student sample, as well as the relationship between hoarding and OCD-base scrupulosity. Study 2 examined the psychometric properties of the MOMS in a replication of study 1 with a sample of people with hoarding problems. Study 3 examined the reliability and validity of the MOMS in a large nonclinical/community sample.Findings across the studies provided evidence for the reliability and validity of the MOMS. It was highly correlated with hoarding symptoms, especially difficulty discarding, and hoarding related beliefs, especially responsibility beliefs. It accounted for significant variance in hoarding symptoms independent of other correlates, including other hoarding beliefs. OCD-based scrupulosity was correlated with hoarding in sample 1, but not in the hoarding sample in study 2.Material Scrupulosity refers to an exaggerated sense of duty or moral/ethical responsibility for the care and disposition of possessions to prevent their being harmed or wasted. It appears to be distinct from other hoarding-related beliefs and a significant predictor of hoarding symptoms. The MOMS appears to possess good reliability and validity in both clinical and nonclinical samples.