Nanoprecipitation of curcumin from its ethanolic solutions was carried out at a microfluidic scale by the liquid anti-solvent technique, in the presence of SDS as a stabilizer. Attention was mainly paid to the mixing angle of the water and ethanol in three micro-fabricated channels. The nanosuspension quality was measured by particle size distribution and polydispersity index. BET surface area, dissolution test, FTIR spectra, and XRD patterns of the optimized nanosuspension were also evaluated experimentally. In particular, narrow size distribution of curcumin particles was achieved under well-controlled conditions of large confluence angles. The amorphous ultrafine curcumin powder exhibited enhanced dissolution properties when compared to the raw material. To explain the precipitation results, a species 3D model was created by computational fluid dynamics (CFD). The pressure drop was compared to the quantitative experimental data to validate the CFD computations. Altogether, the similarities in observations and the mass fraction and velocity predictions of the 3D model revealed that the injection angle of microfluidic devices is a key parameter for the resultant curcumin nanoparticle size.