In this paper, we present a new text line detection method for unconstrained handwritten documents. The proposed technique is based on a strategy that consists of three distinct steps. The first step includes preprocessing for image enhancement, connected component extraction and average character height estimation. In the second step, a block-based Hough transform is used for the detection of potential text lines while a third step is used to correct possible false alarms. The performance of the proposed methodology is based on a consistent and concrete evaluation technique that relies on the comparison between the text line detection result and the corresponding ground truth annotation.