(1) Background: During the second wave of COVID-19, India faced a rapid and sudden surge of not only COVID19-delta variant cases but also mucormycosis, making the infection even more fatal. We conducted a study to determine factors associated with the occurrence of mucormycosis in patients with COVID-19. (2) Methods: This case–control study comprised 121 patients; 61 cases (mucormycosis with COVID-19) and 60 controls. Patients were included from April 10, 2021 onwards. Follow-up was conducted after about 90 days and health status was recorded based on the modified Rankin Scale (mRS). (3) Results: Mucormycosis with COVID-19 cases had a median (IQR) age of 49 (43–59) years with 65.6% males and were older (95% CI 1.015–1.075; p = 0.002) than in the control group with median (IQR) 38 (29–55.5) years and 66.6% males. Baseline raised serum creatinine (OR = 4.963; 95% CI 1.456–16.911; p = 0.010) and D-dimer (OR = 1.000; 95% CI 1.000–1.001; p = 0.028) were independently associated with the occurrence of mucormycosis in COVID-19 patients. Additionally, diabetes mellitus (OR = 26.919; 95% CI 1.666–434.892; p = 0.020) was associated with poor outcomes and increased mortality in patients with mucormycosis with COVID-19 as per the multivariable analysis. A total of 30/61 mucormycosis patients had intracranial involvement. (4) Conclusions: The study observed elevated levels of baseline raised creatinine and D-dimer in mucormycosis pa-tients with COVID-19 as compared to the control group. However, future studies may be conducted to establish this cause–effect relationship.