Exercise stage of change (ESOC), or readiness to exercise, has been measured using at least 13 instruments and 4 interviews, yet no comparison studies are available to determine optimal measures for use by health care providers. This pilot study compares ESOC classification between 3 instruments (scale-ladder, scale-true/false, and scale-5 choice); explores the feasibility of using a face-to-face structured interview; compares classification between instruments and interview; and examines the influence of sex, age, and education level on stage classification. Thirty healthy adults completed ESOC instruments in random order and then the interview. Scale-ladder and scale-true/false instruments exhibited almost perfect agreement (weighted kappa, 0.897). All instruments exhibited substantial agreement with interview (weighted kappa, 0.620-0.790). Stage classification did not differ significantly by sex, age, or education level. The authors recommend word clarification revision of the scale-5 choice instrument and further testing of the interview.