The purpose of this 12-week pre-post design study was to assess the impact of Motivational Interviewing via Co-Active Life Coaching (MI-via-CALC) on engagement in physical activity for 25 women between the ages of 30 and 55 years. Data on task self-efficacy, barrier-specific self-efficacy, self-esteem, physical activity (PA), body mass index (BMI), and waist-to-tip ratio and circumference were collected. Results indicated some positive, but not significant differences in barrier-specific self-efficacy, which were detected between pre- and post- intervention, and statistically significant differences in self-esteem between pre- and post-intervention were found. No statistically significant differences were found in participants’ task self-efficacy scores and PA scores. Statistically significant decreases were detected for BMI, and waist-to-hip ratios and circumference. MI-via-CALC is an encouraging approach for women who are seeking a more physically active lifestyle, and additional research with a larger sample size is recommended.