Tofacitinib, an oral Janus kinase inhibitor, has demonstrated teratogenic effects in animal models. However, there is a lack of data on its effects during human pregnancy, especially in the context of synovitis, acne, pustulosis, hyperostosis, osteitis (SAPHO) syndrome, a rare disease. We report a case of a 31-year-old female patient with SAPHO syndrome who became pregnant unexpectedly after 5 weeks of continuous tofacitinib treatment during the first trimester. Tofacitinib was immediately discontinued upon discovering the pregnancy. The patient successfully delivered a healthy full-term male infant under vigilant monitoring, and her SAPHO syndrome symptoms ameliorated during gestation but exacerbated 40 days postpartum. Given the limited clinical data available, further monitoring of pregnancy outcomes in patients treated with tofacitinib is still warranted.