The monitoring of increased intracranial pressure (ICP) is desirable in the diagnosis and treatment of patients suffering from traumatic brain injury (TBI) or hydrocephalus, for it can provide an insight into the mechanism of the head injury. Therefore we developed a novel miniature diaphragm-based Fabry-Perot (F-P) sensor for ICP measurement. The presented sensor exhibits a linear response to the applied pressure over the range of 0~25 kPa, with a sensitivity of 39.2 nm/kPa and a resolution of 0.13 kPa. In addition, we offered two kinds of packaging methods. Compared with the sophisticated process involved in making a commercially available fiber optic sensor for ICP monitoring, the reported sensor is simple to be fabricated and low-cost.