In patients receiving treatment for cardiac sarcoidosis (CS), it was unknown how the left ventricular ejection fraction (LVEF) would progress over time. Patients diagnosed with CS receiving treatment with corticosteroids and who underwent transthoracic echocardiography were the study subjects. Retrospective evaluation of baseline features, therapy, echocardiographic data (including baseline to follow-up change in LVEF), and outcomes. About 55 of 100 patients had reduced LVEF (<50%) at baseline, whereas 45 had intact LVEF (≥50%). At follow-up, LVEF was either maintained or improved in 82% of patients. Change in LVEF was substantially greater in the group with reduced LVEF at baseline than in the group with intact LVEF (5% [interquartile range 0 to 15%] versus 0% [interquartile range -10% to 5%], P=0.001). There was no difference in corticosteroid exposure or use of medicinal therapy based on heart failure guideline recommendations between patients whose LVEF improved and those whose LVEF did not improve. On multivariable analysis, reduced LVEF at baseline (odds ratio 54.89, 95% CI 3.84 to 785.09, P=0.003) and complete heart block at presentation (odds ratio 28.88, 95% CI 2.17 to 383.71, P=0.011) were significantly associated with reduced LVEF after treatment. In conclusion, most CS patients maintained or improved their left ventricular (LV) systolic performance while taking corticosteroids. Regardless of the treatment, cardiac characteristics at presentation impacted the clinical course of CS.