Background: Regular physical activity is important for patients with established coronary heart disease as it favourably influences their coronary risk profile. General self-efficacy is a powerful predictor of health behaviour change that increases in physical activity levels. Few studies have simultaneously measured physical activity and self-efficacy during early recovery after the first Acute Myocardial Infarction (AMI). Purpose: 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: Using a repeated measures design a purposive sample of patients diagnosed with first AMI, who did not have access to cardiac rehabilitation was recruited from a single centre in Jordan. A body-worn activity monitor (activPAL) was used to objectively measure free-living physical activity levels for seven 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 ANOVA were used to examine differences in physical activity levels and cardiac self-efficacy scores respectively. Results: A sample of 100 participants was recruited, 62% were male with a mean age of 54.5 years ± 9.9 years. There was no statistically significant difference in physical activity levels measured at (T2) two weeks and (T3) six weeks. 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 behaviour change. This study provides a first step in understanding the complex relationship between cardiac self-efficacy and physical activity in this population. These findings could support the design of culturally appropriate interventions to increase physical activity levels in this population.