"Nepenthes rigidifolia" has a racemose inflorescence. Female inflorescences have not been recorded in the wild. In male inflorescences, the rachis measures around 3.9 cm in length and the peduncle around 4.2 cm. Bracts are approximately 9 mm long by 4 mm wide. Flowers are produced on two-flowered partial peduncles bearing basal bracteoles up to 2 mm long. The unbranched portion of the partial peduncles is up to 5 mm long. The pedicels themselves are up to 6 mm long. Tepals are ovate-oblong and measure up to 5 mm in length by 3 mm in width. The androphore is around 4 mm long and 1 mm in diameter. "Nepenthes rigidifolia" is one of the few "Nepenthes" species known to occasionally produce multiple inflorescences concurrently on a single stem. This unusual reproductive habit has also been observed in "N. alba", "N. ampullaria", "N. attenboroughii", "N. benstonei", "N. philippinensis", "N. sanguinea", and "N. thai".