The purpose of this study was to evaluate psychological, biophysical, and sociodemographic variables as predictors of adherence to glatiramer acetate (Copaxone) therapy in individuals with self-reported progressive forms of multiple sclerosis (MS). The literature lends support for self-efficacy, self-esteem, hope, and disability to be predictors of adherence. Therefore the hypotheses for this study were (a) higher self-efficacy will be a significant predictor of adherence, (b) higher self-esteem will be a significant predictor of adherence, (c) higher hope will be a significant predictor of adherence, and (d) a lower level of disability will be a significant predictor of adherence. The MS Self-Efficacy Scale (MSSE), Rosenberg Self-Esteem Scale, Herth Hope Index, and Performance Scales; a sociodemographic questionnaire; and an information sheet regarding consent to participate in the study were mailed to 1,200 potential participants. A total of 594 individuals responded, and for the evaluation of predictors of adherence in individuals with self-reported progressive forms of MS, 199 met the criteria. Logistic regression analysis revealed four significant predictors of adherence: the MSSE Control subscale, MSSE Function subscale, perceived support of the physician, and perceived support of the spouse. The higher the score on the MSSE Control subscale, the more likely the individual will adhere to glatiramer acetate therapy. The higher the score on the MSSE Function subscale, the more likely the individual will adhere to glatiramer acetate therapy. The MSSE Control and Function subscales show promise of being useful to predict adherence.