The Arroyo Urugua-í, also known as the Arroyo Grande, originates in the Sierra de Misiones near the city of Bernardo de Irigoyen and flows westward to empty into the Río Paraná south of Puerto Bosetti and northwest of Puerto Libertad, in the Iguazú department of Misiones, Argentina. The watershed is one of the most extensive in the province, bounded by the Sierras Morena, de Misiones, and de la Victoria, and encompasses portions of the Iguazú and General Belgrano departments. The arroyo carries a mean discharge of 54 m³/s.

The upper and middle sections of the watershed fall within the Parque Provincial Urugua-í, and park rangers (guardaparques) have organized descents departing from the Reserva de Vida Silvestre Urugua-í and running to the confluence with the Arroyo Falso. These trips have been conducted with wildlife observation and hydrological survey as primary objectives, suggesting that access to the upper reaches may require coordination with park authorities. A hydroelectric dam exists on the arroyo and would represent a significant obstacle for any through-paddling route; its precise location relative to common put-in and take-out points should be confirmed before planning a descent.