SFTPC (surfactant protein C) mutations resulting in SP-C deficiency causing ongoing respiratory failure in the neonatal period represent a rare entity. We report a full-term female infant who developed respiratory distress and respiratory failure shortly after birth. From the first day of life the infant was mechanically ventilated. Application of exogenous surfactant or cortisone did not lead to any clinical improvement. Genetic analysis identified a novel SFTPC mutation as the cause of her lung disease. The patient was diagnosed as heterozygous for a p.Cys121Gly/C121G substitution encoded by exon 4, which could not be detected in both parents. Experimental therapy with hydroxychloroquine resulted in a significant clinical improvement within 2 weeks time. Mechanical ventilation was no longer needed, and the patient was discharged without additional oxygen demand. The patient remained well under therapy till the age of 6 months. After that time, the therapy was successfully discontinued.