The present disclosure relates to a process for preparing fluorescent carbon based quantum dots. The fluorescent carbon based quantum dots are prepared by introducing a carbon-containing compound in a reactor and subjecting the carbon-containing compound to shear mixing at a speed in the range of 16000 rpm to 20000 rpm to obtain a dispersion comprising fluorescent carbon-based quantum dots. The process of the present disclosure is simple, rapid, economical, provides better control over obtaining the desired concentration of carbon quantum dots, is highly scalable, and does not require any post-synthetic treatment or severe synthetic condition.