A suboccipital puncture or cisternal puncture is a diagnostic procedure that can be performed in order to collect a sample of cerebrospinal fluid (CSF) for biochemical, microbiological, and cytological analysis, or rarely to relieve increased intracranial pressure. It is done by inserting a needle through the skin below the external occipital protuberance into the cisterna magna and is an alternative to lumbar puncture. Indications for its use are limited.