Despite limited pediatric-specific interventional data, the pathophysiology and biochemistry of cystinuria support foundational nutritional strategies in children that are analogous to those used in adults but adapted to pediatric growth and body size. Cystine is poorly soluble in urine, and impaired renal tubular cystine reabsorption leads to increased urinary cystine concentration, supersaturation, crystallization, and clinical stone formation. Preventive strategies therefore focus on reducing urinary cystine concentration and increasing cystine solubility, with high urine volume as the cornerstone of therapy. Because cystine solubility is concentration-dependent, pediatric patients with cystine stones should be encouraged to maintain fluid intake sufficient to achieve a urine output of >40 mL/kg/day. This weight-based target accounts for variation in body size and is more appropriate for children than a fixed adult urine volume goal, particularly for younger or smaller patients. The higher urine output target for cystine stones compared with calcium stones reflects the uniquely poor solubility of cystine and the need for aggressive urinary dilution to reduce supersaturation and crystallization. Limited salt intake is also recommended for children with cystine stones because urinary cystine excretion is linked to renal sodium handling, and reduction in dietary sodium intake has been associated with lower urinary cystine excretion in cystinuria literature.217 Although adult dietary recommendations may also include moderation of animal protein intake, routine animal protein restriction is not included in this pediatric recommendation because children require adequate protein intake for growth and development, and pediatric evidence demonstrating benefit from animal protein restriction is limited. While alkalinization and thiol-binding agents are often required in patients with recurrent stones refractory to high fluid intake and dietary sodium reduction, high fluid intake and limited salt intake represent essential first-line, low-risk interventions for all children with cystine stones.