The study reported in this paper investigated the structure of the health locus of control beliefs of elementary school children using second-order factor analysis and the measurement characteristics of the Multidimensional Health Locus of Control (MHLC) Scales. Changes of wording were made in 10 of the MHLC Scales items in order to improve the readability of the measure. Subjects were two groups of fourth- through sixth-grade students from four elementary schools in a large urban school district in the southern United States. All schools had average academic achievement profiles. The first sample included 1,028 subjects (501 males and 527 females) who completed the 18 items on the revised MHLC Scales. The second sample included 524 subjects (264 males and 260 females) who, 1 year later, completed the 18 MHLC Scales items and an additional six items (two per scale) developed by G. S. Parcel and M. P. Meyer (1978). A total of 248 subjects were common to both samples. Separate analyses were conducted for the two groups in order to examine result stability. The results shed light on the validity of the MHLC Scales as well as on the nature of locus of control beliefs in general. A 33-item list of references, 9 data tables, and 1 figure are provided. A checklist of items used in the study instrument is appended. (TJH)