Disclosed is a device for collecting rainwater in a pergola including posts, a frame with beams and slats, arranged transversely, parallel to each other, the slats being articulated about a substantially median axis and being capable of assuming a substantially vertical position and a substantially horizontal position, manual or motorised unit ensuring the coordinated movements of the slats. The device includes a movable unit, rigidly connected to the slats Ln, including longitudinal deflectors.