Introduction We report a case of pneumocephalus, which is identified as the presence of air in the cranial cavity and is a rare complication after spinal surgeries, in addition to a literature review of similarly reported cases. Case presentation The patient is a 63-year-old male who developed pneumocephalus after undergoing a minimally invasive left side decompression at L3-L4 with left L4 foraminotomy even though there were no signs of dural tears or Cerebrospinal Fluid (CSF) leaks. After the diagnosis of pneumocephalus using brain Magnetic Resonance Imaging (MRI), the patient was treated conservatively and was discharged after 3 weeks without developing further complications. Discussion Pneumocephalus is defined as an abnormal accumulation of air within the cranial cavity. It can occur due to a variety of causes but rarely due to gas forming bacteria. Many theories are suggested concerning the pathophysiology of pneumocephalus, the inverted bottle theory, the ball valve theory, the Nitrous Oxide (N 2 O) theory, and as we outweigh in our case, gas forming bacteria theory. Pneumocephalus can be treated surgically, nevertheless, conservative management methods of such cases are usually followed. Conclusion The aim of this study is to draw further attention to the management and diagnosis of such surgical complication. A more extended research is needed to provide a full comprehensive approach to deal with this problem if faced in the future. To the best of our knowledge, this study reports the first pneumocephalus case induced by a postoperative bacterial infection in the global English based medical literature.