This study examined the effects of a motivational interviewing (MI) intervention on physiological outcomes among hyperlipidemic persons randomly assigned to an MI (n = 12) or an attention-control (AC; n = 12) group. Lipid and cardiorespiratory fitness levels were measured pre- and postintervention. The MI intervention was significant in reducing total cholesterol and low-density-lipoprotein cholesterol but not in increasing VO(2max) when compared with the AC group. Contrary to what was expected, the MI intervention significantly reduced high-density-lipoprotein cholesterol. Although this study was limited by a small sample size, findings suggested that an MI telephone session can have a positive effect on lipid profiles and fitness levels.