Results of in-situ high pressure x ray diffraction measurements on 5 nm SnO₂ nanoparticles are reported. The ambient rutile phase remains stable upto the pressure of 18.1 GPa. However, beyond 19 GPa, the diffraction pattern shows the new diffraction peaks indicating the presence of structural phase transition in the material. These new peaks could be assigned to cubic structure. The coexistence of both the phases could be seen over a large pressure region indicating the sluggishness of the transition.