BACKGROUND: Regular physical activity is important for patients with established coronary heart disease as it favorably influences their coronary risk profile. General self-efficacy is a powerful predictor of health behavior change that involves increases in physical activity levels. Few studies have simultaneously measured physical activity and self-efficacy during early recovery after a first acute myocardial infarction (AMI). PURPOSE: The aims of this study were to assess changes in objectively measured physical activity levels at 2 weeks (T2) and 6 weeks (T3) and self-reported cardiac self-efficacy at hospital discharge (T1) and at T2 and T3 in patients recovering from AMI. METHODS: A repeated-measures design was used to recruit a purposive sample of patients from a single center in Jordan who were diagnosed with first AMI and who did not have access to cardiac rehabilitation. A body-worn activity monitor (activPAL) was used to objectively measure free-living physical activity levels for 7 consecutive days at two time points (T2 and T3). An Arabic version of the cardiac self-efficacy scale was administered at T1, T2, and T3. Paired t tests and analysis of variance were used to examine differences in physical activity levels and cardiac self-efficacy scores, respectively. RESULTS: A sample of 100 participants was recruited, of which 62% were male. The mean age of the sample was 54.5 ± 9.9 years. No statistically significant difference in physical activity levels was measured at 2 weeks (T2) and 6 weeks (T3). Cardiac self-efficacy scores improved significantly between T1, T2, and T3 across subscales and global cardiac self-efficacy. CONCLUSIONS/IMPLICATIONS FOR PRACTICE: Participants recovering from AMI in Jordan did not increase their physical activity levels during the early recovery phase, although cardiac self-efficacy scores improved. This may be because the increase in cardiac self-efficacy was not matched by the practical skills and knowledge required to translate this positive psychological construct into behavioral change. This study provides a first step toward understanding the complex relationship between cardiac self-efficacy and physical activity in this population. The authors hope that these findings support the design of culturally appropriate interventions to increase physical activity levels in this population.