A dry tap is one of the complications of lumbar puncture. Dry taps commonly result from misplacement of the spinal needle. The most common misplacement is the lateral displacement which is readily rectified by completely withdrawing the needle, reevaluating the patient's anatomy, and reinserting the needle at the proper location and angle. Moreover, the standard spinal needle may be too short in obese people, in which case a longer one should be utilized. However, a falsely negative dry tap may be obtained due to dehydration in the patient which causes low cerebrospinal fluid volume and pressure. When this condition is suspected, the patient is rehydrated before the procedure.