A method of making sintered abrasive particles includes passing alumina precursor particles through a flame under conditions such that they are converted to alpha alumina. The precursor particles comprise a precursor of alpha alumina and have an average particle size of less than or equal to 500 microns. Sintered abrasive particles have a cellular microstructure comprising alpha alumina crystal grains of alpha alumina having a maximum dimension of less than about 3 microns are also disclosed. The sintered abrasive particles have an average particle size of less than or equal to 500 microns, and are essentially free of seed particles and alpha alumina grain size modifiers. Abrasive articles comprising a binder and a plurality of the sintered abrasive particles are also disclosed.