Abstract Aim. This review evaluated the effects of activity monitor- counseling on physical activity (PA) and generic and disease-specific health-related outcomes in adults with diabetes mellitus type II (DMII), obstructive pulmonary disease (COPD), or chronic heart failure (CHF). Four electronic databases were searched for randomized controlled trials activity monitor-based counseling versus control intervention or usual adults with DMII, COPD, or CHF. Pooled effect sizes were calculated random effects model. Results. Twenty-four articles were included: 21 studies and 3 COPD studies. No CHF studies were identified. Pooled showed that activity monitor-based counseling resulted in a improvement in PA compared to control intervention or usual care in Furthermore, these interventions had a beneficial effect on hemoglobin (HbA1c), systolic blood pressure, and body mass index (BMI) (P < 0.05), no differences were found on diastolic blood pressure, and health- of life. Meta-analysis of COPD studies was not possible due to lack of data. Conclusion. Activity monitor-based counseling had a beneficial PA, HbA1c, systolic blood pressure, and BMI in patients with DMII. Data patients with COPD and CHF are limited or non-existing, respectively.