This paper presents the Aging Sexuality Knowledge and Attitudes Scale (ASKAS), an instrument designed to assess the particular aspects of sexual knowledge and attitudes as they relate to the aged. Development of ASKAS items from a survey of existant physiological research on sexuality in older adults and a review of social-psychological writing on aged sexuality is described. Unique features of the ASKAS are discussed, including its focus on issues of the aged, the contexts of aged persons, and the sexual changes unique to the aged. The ASKAS format is described and administration and scoring procedures are given. Reliability data is presented from studies which used the ASKAS with aged persons, families of aged persons, and persons who work with the aged. The findings are discussed, supporting the validity and reliability of the scale in assessing sexual attitudes and knowledge with specific reference to the aged. Studies are cited which report significant changes in scale scores following intervention, and significant relationships of sexual behavior to scale scores which follow predicted directions. A factor analysis is presented that supports the two dimensions of attitudes and knowledge. A copy of the ASKAS is included with correct answers given for knowledge items. (Author/NRB)