The new type of coronavirus could cause severe acute respiratory syndrome and injuries in other systems as well. Multiple organ damage can occur rapidly in patients infected with coronavirus disease 2019 (COVID‐19). Previous studies have shown that many laboratory biomarkers were not within the normal ranges in COVID‐19 patients. We aimed to summarize laboratory parameters and the tumor markers in COVID‐19 patients. This is a retrospective cohort study conducted on 53 women between the ages of 19–85 years infected with COVID‐19 at a training and research hospital between May 2020 and August 2020. Of the 53 women, 16 (30.2%) had leukopenia. The mean C‐reactive protein level was 18.42 ± 59.33 mg/L. The mean procalcitonin level was 0.1 ± 0.21 µg/L. The liver function tests were within normal limits. The mean creatinine level was 0.58 ± 0.37 mg/dl. Elevated levels of α‐fetoprotein (AFP) in 1 patient, elevated levels of carcinoembryonic antigen (CEA) in 2 patients, elevated levels of cancer antigen 125 (CA125) in 4 patients, elevated levels of CA19‐9 in 2 patients, and elevated levels of CA15‐3 in 2 patients were detected. One of 4 patients who were taken to the intensive care unit had elevated levels of AFP. In addition, 2 of 4 patients who were taken to the intensive care unit had elevated levels of CA125 and CA15‐3. Except for AFP, levels of all tumor markers of the patient who died were high. We found that COVID‐19 had no effect on tumor markers (CA125, CA19‐9, CA15‐3, AFP, and CEA).