Spinal anesthesia is the procedure of choice for caesarean section. There is no risk of airway hazards، such as difficult airway intubation and aspiration in this method. Some cases avoid to choose this method، because of fear of complications specially headache. This Study has been done to assess the true extent of headache after surgery with spinal anesthesia and its related factors. This cross-sectional analytic study was done in 2011 for one year in 22th of Bahman hospital of Gonabad. 200 pregnant women that was candidate for caesarean section under spinal anesthesia were selected by achievable and purposeful sampling method. All procedure was performed in a sitting position and with a disposable 25-gauge needle with 75mg Lidocaine 5% and 25 micrograms Fentanyl. Data were gathered and analyzed using the SPSS 11. 5 software and independent T and Chi-square tests. 12 patients (6%) in 24 hours after spinal anesthesia and 44 cases (22%) in first week after spinal anesthesia experienced headache. Headache happening had a significant relationship with body mass index (p=0. 028) and occupational factors (p=0. 011) in the first week. Hypotension was the most complication (52. 5%) during spinal anesthesia. Hypotension is the most complications during spinal anesthesia. Those with higher body mass index and those who were employed are at higher risk for headache in first week after spinal anesthesia.