Hydrodynamic focusing is a widely used tool in microfluidics world. Typical working models are treating this phenomenon as two-dimensional, however the requirements of high throughput analysis show the urgent need to operate in higher Reynolds number range Re > 10, where the three dimensional effects are no longer negligible. Current work, based on both experimental results of confocal laser scanning microscopy (CLSM) and computational fluid dynamics (CFD) modeling describes the problematic range of flow parameters and presents the model describing the shape of the focused stream. In specific, the discussion is aimed at possible use of the proposed solution in single particle rheology, where such a model gives novel control possibilities over the experimental parameters.