Sepsis is a common and life-threatening inflammatory response to severe infection treated with antibiotics and fluid resuscitation. Despite the central role of intravenous fluid in sepsis management, fundamental questions regarding which fluid and in what amount remain unanswered. Recent advances in understanding the physiologic response to fluid administration, and large clinical studies examining resuscitation strategies, fluid balance after resuscitation, colloid versus crystalloid solutions, and high- versus low-chloride crystalloids, inform the current approach to sepsis fluid management and suggest areas for future research.