The invasion of Theileria sporozoites into bovine leukocytes is rapidly followed by the liberation of the parasite from the parasitophorpous vacuole membrane, allowing the parasite to establish its niche within the host cell cytoplasm. Theileria infection induces host cell transformation, characterised by increased host cell proliferation and invasiveness, and the activation of anti-apoptotic genes. This process is strictly dependent on the presence of a viable parasite. Several host cell kinases, including PI3-K, PKA, CK2 and Src-family kinases, are known to be constitutively activated in Theileria infected cells and to contribute to the transformed phenotype. A number of host cell molecules, including the IB kinase and polo-like kinase 1 (Plk1), are recruited to the schizont surface, although very little is known about the schizont molecules involved. In this study we used immunofluorescence analysis to detect phosphorylated threonine (p-Thr and p-Thr-Pro) and serine (p-Ser) epitopes on the schizont during host cell cycle progression, revealing extensive schizont surface phosphorylation during host cell interphase. Further, we isolated schizonts from infected macrophages following synchronisation in S-phase or mitosis, and used mass spectrometry to detect phosphorylated schizont proteins. In total, 65 phosphorylated Theileria proteins were detected, 15 of which are potentially secreted or expressed on the surface of the schizont and thus mayight be targets forof host cell kinases. In particular, we describe the cell-cycle stage phosphorylation of two T. annulata surface expressed proteins, TaSP and p104. Phospho-peptides of both proteins were significantly more abundant in schizonts purified from S-phase cells.