The oxalate content of guava and sapota fruits at different stages of ripening were found out by permanganometric method. Oxalate rich foods are usually restricted to some degree, particularly in patients with high urinary oxalate level. Guava and sapota fruit have the highest percentage of vitamin C among citrus fruits. It also contains oxalate amount of which varies with ripening of the fruit. During ripening of guava and sapota fruit; the oxalate content increases progressively and the fully ripe fruit has the maximum oxalate content. Oxalate form an insoluble complex with calcium in the urine, or hyper-oxaluria, is even more important to stone formation than high levels of calcium or hypercalcicuria. Excessive intake of food and drink containing oxalate leads to calcium oxalate stone. Also, excessive intake of vitamin C which metabolized to oxalate may lead to hyper calcicuria and an increase in stone formation. Pain medications can be prescribed for symptom relief. Surgical techniques have also been developed to remove kidney stones.