This paper presents a direct numerical simulation (DNS) of turbulent flow over a rectangular trailing edge geometry at a Reynolds number of 1000 based on the trailing edge thickness. The study is earned out first with a turbulent boundary layer flow calculation, producing time-dependent data for the inflow condition, followed by the turbulent trailing edge flow simulation. A parallel simulation code is used, which is based on a finite difference scheme and a multi-grid Poisson solver. The computed flow has been studied for the effects of domain size and grid resolution. Comparison of the mean quantities and turbulence statistics has been made. The characteristics of vortex shedding are revealed by the time history of lift and pitching moment and their power spectra, from which the main shedding frequency (nondimensionally equal to 0.1) is clearly shown together with other harmonic frequencies. A series of instantaneous flow structures in a shedding period is visualized, providing further understanding of the shedding dynamics and the interaction between the pressure field and vortices in the near wake region. A high-resolution simulation with a total of 256 × 512 × 64 grid points in the computational domain is carried out to analyse the energy budget in both the boundary layer and wake regions.