Tumor infiltrating immune cells in cancer, such as lymphocytes, have been studied in last years and evidence shows them to be related with the disease prognosis. Knowing the distribution and localization of these cells is of especial interest for pathologists and nowadays involves manual counting on Immunohistochemistry (IHC) Images. This work presents a model based on Deep Convolutional Neural Networks to automatically detect and count lymphocytes on IHC Images of gastric cancer as well as an lymphocyte images database for future work.