There has been a long debate whether subjectively "free" decisions are determined by brain activity ahead of time. Previous claims that subjective decisions are preceded by brain activity have been highly criticized as inaccuracies in the participants' subjective reports. Also, it has remained unclear whether an intention to act is initiated in motor-related brain regions, or if high-level brain areas are involved. Here we use a combination of statistical pattern recognition and fMRI to show that the outcome of decisions can be decoded from brain activity in prefrontal and parietal cortex even up to ten seconds before they enter awareness. This delay is too long to be accounted for by inaccuracies in measuring the onset of conscious intentions. Instead it presumably reflects the operation of a network of high-level control areas that operate at a slow timescale and begin to prepare an upcoming decision long before it enters awareness. This suggests that our free choices can be determined by brain activity much earlier than commonly appreciated.