Sexual distress is an important factor in the etiology, maintenance, and treatment of sexual difficulties, and as such, there is a need for validated measures. A limitation in the research and treatment of distressing sexual difficulties has been the lack of validated measures, and in particular, existing measures are unable to measure the impacts at the relationship level and currently focus on intra-personal distress.This study sought to develop and psychometrically evaluate a new measure of distress associated with sexual difficulties.An initial pool of 73 items was created from the results of an earlier qualitative study and administered using an online survey to 1,381 participants (462 men, 904 women, and 14 who identified as "other"), along with measures for the purposes of psychometric evaluation including the Female Sexual Distress Scale-Revised, Couples Satisfaction Index 16-item version, Depression Anxiety and Stress Scale-Short Form, and questions relating to sexual function. Exploratory factor analysis and confirmatory factor analysis in separate split-half samples were conducted, followed by analysis of validity and reliability of the resulting measure.The Sexual and Relationship Distress Scale (SaRDS) was developed to meet the need for a patient-reported outcome measure of individual and relationship distress within the context of sexual dysfunction and resulted in a psychometrically sound 30-item, 14-factor measure of sexual and relationship distress.The final 30 items explained 77.5% of the total variance and the confirmatory factor analysis showed that this model has an adequate fit (comparative fit index = .97, normed fit index = .95, root mean square error of approximation = .05). The final measure demonstrated good psychometric properties, with strong internal reliability (Cronbach alpha = .95 for the total score with individual sub-scales ranging from .70-.96), and convergent and discriminant validity when compared to current measures (Female Sexual Distress Scale-Revised, r = .82, P < .001; Couples Satisfaction Index, r = -.69, P < .001; Depression Anxiety and Stress Scale-Short Form, r = .37, P < .001).The SaRDS may prove useful for researchers and clinicians interested in understanding and improving the distress experienced within the context of sexual difficulties. The new measure is brief (30 items), easy to administer and score, easily understood (Flesch-Kincaid reading level = grade 3.9), and demonstrates high internal consistency, convergent and discriminant validity.The SaRDS has advantages over existing measures as it is brief yet includes sub-scales. However, it must be noted that a community sample was used for this study and it would be beneficial to include a clinical sample in future validation studies.Unlike most measures in this field, the SaRDS is multi-dimensional and assesses 14 distinct yet related types of sexual and relationship distress experienced in the context of sexual dysfunctions. It can be administered across genders and both members of a couple. It therefore has multiple uses within both research and clinical settings. Frost R, Donovan C. The Development and Validation of the Sexual and Relationship Distress Scale. J Sex Med 2018;15:1167-1179.