In particular, our approach enables robust automatic determination of cell cycle phase durations which allows automatically analyzing large-scale screening experiments to study mitotic gene regulation. To this end, we developed a complex image analysis workflow comprising of methods for segmentation, tracking, feature extraction, classification into cell cycle phases, and phase sequence parsing. Our approach was applied to a large number of real images from four different screens. In total, we analyzed more than 1000 image sequences with around 100 to 200 time steps each. The experimental evaluation showed that our approach robustly and accurately solves different tasks: (1) classification of cell nuclei into different cell cycle phases, (2) determination of cell cycle phase durations, and (3) classification and quantification of morphological phenotype classes. In our experiments we also demonstrated the applicability of our approach for different biological settings by analyzing images of different cell lines and images of different screening microscopes.