Urolithiasis is a common chronic disorder affecting humans which is characterized by the formation of stones in the urinary tract. The most common stone is made up of calcium oxalate which is caused by excess calcium in urine. The main objective of the study is to determine the inhibitory effect of lemon grass (Andropogen citrates) hydroalcoholic extract on crystal growth and aggregation of calcium oxalate in synthetic urine. This may be considered a new approach to prevent urolithiasis. The inhibition of crystal formation was observed using a compound microscope by measuring the reduction of size and number of crystals in synthetic urine. This reduction was also observed on the change in turbidity at 620 nm by means of a spectrophotometer. Various concentrations of the extract were used to get the greatest percentage of inhibition. The researchers concluded that Andropogen citrates acted on the calcium oxalate crystal growth stage, therefore, inhibiting further aggregation of the crystals to form stones. The researchers further conclude that the degree of inhibition increased as the concentration of the Andropogen citrates extract increased from 25%, 50%, 75%, with the greatest inhibition at 100% concentration. In general, Andropogen citrates leaf extract had inhibitory effect on calcium oxalate crystal growth, hence, it may be a treatment for urolithiasis specifically calcium oxalate stones.