We investigate the electronic structure of Ca1−xSrxVO3 using photoemission spectroscopy. Core level spectra establish an electronic phase separation at the surface, leading to distinctly different surface electronic structure compared to the bulk. Analysis of the photoemission spectra of this system allowed us to separate the surface and bulk contributions. These results help us to understand properties related to two vastly differing energy-scales, namely the low energy-scale of thermal excitations (∼ kBT ) and the high-energy scale related to Coulomb and other electronic interactions.PACS numbers 71.30.+h, 71.27.+a, 73.20.At, 79.60.Bm The electronic structure of strongly correlated transition metal oxides has attracted a great deal of attention both theoretically [1] and experimentally [2] due to many exotic properties exhibited by these systems such as high temperature superconductivity and colossal magnetoresistance. In order to investigate such issues, photoemission spectroscopy has been extensively employed due to its ability to probe the electronic structure directly. While this technique is highly surface sensitive as observed in rare earth intermetallics [3], its extensive use to understand the bulk properties of transition metal (TM) oxides [4] is based on the implicit assumption of very similar electronic structures at the surface and in the bulk. We observe a spectacular failure of this assumption in Ca 1−x Sr x VO 3 .Ca 1−x Sr x VO 3 is a solid solution of CaVO 3 and SrVO 3 where the bandwidth W can be systematically controlled due to a buckling of the V-O-V bond angle from ∼ 180• in SrVO 3 to ∼ 160. Thus, Ca 1−x Sr x VO 3 is ideally suited for the systematic study of the competition between local interactions and itineracy, which leads to several strong correlation effects. This system is arguably the simplest strongly correlated transition metal oxide, since it remains paramagnetic down to the lowest temperature measured so far (T = 50 mK), has typical Fermi liquid behavior and has nominally just one conduction electron per site of V 4+ . Despite these facts, important aspects of its fundamental physics remain unclear, particularly in terms of its contrasting high-energy spectroscopic and low-energy thermodynamic properties [1,6]. The spectroscopic properties and the thermodynamic properties belong to vastly different energy scales: the former corresponds to a high energy (typically 10 ∼ 10 3 eV) perturbation to the system, while the latter probes electrons typically within k B T (∼ 1 meV) of E F . There is indeed a-priori no reason to believe that the same model physics will be valid in both the regimes.In this study, we observe a strong dependence of the photoemission spectra from Ca 1−x Sr x VO 3 with the escape depth λ of the photoelectrons, siginifying very different surface and bulk electronic structures. The core level spectra exhibit an electronic phase separation at the surface, possibly due to an enhanced correlation effect and leading to a distinctly different surface electronic stru...