Cardiac sarcoidosis (CS) is an important cause of cardiomyopathy. The trajectory of left ventricular ejection fraction (LVEF) in patients with CS undergoing treatment remains unclear. Patients with CS who were treated with corticosteroids and who underwent transthoracic echocardiography were studied. Baseline characteristics, treatment, echocardiographic data (including baseline to follow-up change in LVEF), and outcomes were retrospectively evaluated. Among 100 patients, 55 had baseline reduced LVEF (<50%), and 45 had preserved LVEF (≥50%). At follow-up, 82% of patients demonstrated stable or improved LVEF. Change in LVEF was significantly higher in the baseline reduced than in the preserved LVEF group (5% [interquartile range 0 to 15] vs 0% [interquartile range −10% to 5%], p = 0.001). There was no difference in corticosteroid exposure or use of heart failure guideline-directed medical therapy between patients who did experience improvement in LVEF and those who did not experience improvement in LVEF. On multivariable analysis, baseline reduced LVEF (Odds ratio 54.89, 95% confidence interval 3.84 to 785.09, p = 0.003) and complete heart block (Odds ratio 28.88, 95% confidence interval 2.17 to 383.74, p = 0.011) at presentation were significantly associated with reduced LVEF after treatment. In conclusion, most patients with CS treated with corticosteroids maintain or improve LV systolic function. Cardiac characteristics at presentation impact prognosis in CS, despite treatment.