Abstract Introduction Here we estimate the direct medical costs to the National Health Service (NHS) of unintended pregnancies in 2010 and identify populations at risk for unintended pregnancies. Methods The number of unintended pregnancies in England in 2010 was estimated based on the number of induced and spontaneous abortions, live births and ectopic pregnancies reported by the NHS and Office for National Statistics. Direct medical costs associated with these were obtained from the NHS Reference Costs. Results In 2010, there were an estimated 225,600 unintended pregnancies in England, of which 218,100 were paid for by the NHS. Of these, 155,500 led to induced abortions, 53,900 to births, 7,500 to spontaneous abortions and 1,200 to ectopic pregnancies. These unintended pregnancies cost the NHS £193,200,000 ($299,200,000) in direct medical costs. Discussion London, the North West and the West Midlands should be targeted in efforts to reduce unintended pregnancies. More specifically, women between the ages of 20 and 34 years produce the greatest costs.