This work considers computationally efficient privacypreserving data release. We study the task of analyzing a database containing sensitive information about individual participants. Given a set of statistical queries on the data, we want to release approximate answers to the queries while also guaranteeing differential privacyprotecting each participant's sensitive data.Our focus is on computationally efficient data release algorithms; we seek algorithms whose running time is polynomial, or at least sub-exponential, in the data dimensionality. Our primary contribution is a computationally efficient reduction from differentially private data release for a class of counting queries, to learning thresholded sums of predicates from a related class.We instantiate this general reduction with algorithms for learning thresholds, obtaining new results for differentially private data release. As two examples, taking {0, 1}d to be the data domain (of dimension d), we obtain differentially private algorithms for:1. Releasing all k-way conjunction counting queries (or k-way contingency tables). For any given k, the resulting data release algorithm has bounded error as long as the database is of size at) (ignoring the dependence on other parameters). The running time is polynomial in the database size. The best sub-exponential time algorithms known prior to our work required a database of sizeÕ(d k/2 ) [Dwork McSherry Nissim and Smith 2006].