The invention relates to a clamp (10) for a flexible tube, in particular an infusion tube, composed of a substantially U-shaped plastic band, the free end (111) of the first branch (11) of the U being bent over, so as to form the head (11) of the clamp, to the free end (121) of the second branch, called the back (12), in such a way that, in the closed position, the free end (121) of the back (12) is situated resting under the free end (111) of the head (11), whereas, in the opened position, the free end (121) of the back (12) is situated at a distance above the free end (111) of the head (11), the clamp having a pair of openings (114, 134) to allow a flexible tube to extend through the clamp and be supported by the latter, and two opposite projections (113, 123) for obturating the flexible tube by compressing it when the clamp is in the closed position. The invention also relates to a pump provided with means for opening a clamp according to the invention, to an infusion kit provided with a clamp according to the invention, and to a combination of a pump according to the invention and an infusion kit according to the invention. According to the invention, locking means (112, 122) are provided in order to ensure that the head end (111) does not move away from the back end (121) when the clamp (10) is in the closed position.Linvention concerne une pince de serrage (10) pour une tubulure souple, notamment une tubulure pour perfusion, constituée dune bande de matière plastique essentiellement en forme de U, lextrémité libre (111) de la première branche (11) du U étant cintrée, pour former la tête (11) de la pince, vers lextrémité libre (121 ) de la deuxième branche, appelée dos (12), de sorte quen position fermée, lextrémité libre (121 ) du dos (12) se trouve en appui sous lextrémité libre (111) de la tête (11), tandis quen position ouverte, lextrémité libre (121) du dos (12) se trouve à distance au-dessus de lextrémité libre (111) de la tête (11), la pince ayant une pa
