In this report, we present a new method of aligning histological sections. First a displacement field between the two images is computed by block matching. Then we estimate a rigid transformation based on the field. The process is integrated within a multi-scale scheme. We carefully study the problem of robustness and we propose several ideas to deal with inter-sect- ion intensity differences and background artifacts. We demonstrate experimenta- lly that we can reach a sub-voxel accuracy and we show some results on histological sections of a rat's brain and an endometrical adenocarcinoma.