Background Cerebrospinal fluid (CSF) leakage into the epidural space following lumbar puncture (LP) has been documented in pediatric patients, but there have been no reported cases in adults. Case description We report an epidural CSF leak in an adult who presented with back pain, positional headache, urinary retention, and constipation following an LP performed as a part of a research study. The patient's magnetic resonance (MR) scan showed an extensive epidural CSF collection. Following placement in a recumbent position for 72 h, the collection fully resolved along with his neurological complaints. Conclusion Symptomatic epidural CSF collections rarely occur in adults following LPs. Nevertheless, the management remains the same as for pediatric patients; bed rest for 72 h results typically in full resolution of symptoms/signs and regression of the collection on MR studies.