This document presents a method for lung nodule detection and segmentation from CT images using image processing techniques. The proposed method involves pre-processing the CT images, segmenting the lung region, extracting potential nodules, and classifying nodules. In pre-processing, filters are applied to reduce noise. Region growing and thresholding are used to segment the lungs. Potential nodules are extracted based on size thresholds. Finally, nodules are classified as benign or malignant using features and an artificial neural network algorithm. Experimental results on sample CT images demonstrate each step of the proposed lung nodule detection and segmentation method.