Pneumonia is a type of lung infection that can be caused by bacteria, viruses, or fungi. It is a serious condition that can affect people of all ages, but it is more dangerous for certain populations, such as the elderly, young children, and people with weakened immune systems. Pneumonia can cause higher risk in patients undergoing surgery, including C-sections. In this case report, we present a pregnant woman who was scheduled for a C-section due to preeclampsia and was initially suspected of concomitant pneumonia. The patient successfully underwent the C-section, but unfortunately experienced a deterioration in her pneumonia after the surgery. She was later admitted to ICU and placed on mechanical ventilation due to the deterioration. Despite the acknowledged risks, including the possibility of death, the patient's family chose to bring the patient home due to their belief that there had been no improvement in the patient's condition and a feeling of resignation. In conclusion, pregnant patients who have pneumonia may require an emergency C-section due to several conditions such as preeclampsia, and the C-section can be conducted successfully. However, it is important for physicians to be aware of the potential for the worsening of pneumonia postoperatively. Post-operative pneumonia is a serious condition that can have a significant impact on the health of patients who have undergone a C-section.