The carotenoid composition of Momordica charantia fruit (pericarp) at four levels of maturity was extensively investigated. The number of carotenoids isolated increased from five in the immature fruit to six at the mature-green and 14 at the partly-ripe and ripe stages. Cryptoxanthin, which could not be isolated at the immature and mature stages, accumulated rapidly at the onset of ripening to become the principal pigment of the ripe fruit. Moderate increases were seen in β-carotene, zeaxanthin and lycopene concentrations as ripening progressed. The reverse trend was observed with lutein and α-carotene which were the major pigments of the immature fruit. Prior to the colour break, only the hydroxy derivatives of α-carotene (zeinoxanthin and lutein) could be detected; the β-hydroxy compounds (cryptoxanthin and zeaxanthin) appeared and predominated thereafter. The hydroxy carotenoids of the ripe fruit were almost entirely esterified in contrast to those of the unripe fruit which were mainly unesterified. Traces of flavochrome, 5, 6-monoepoxy-β-carotene, mutatochrome, ζ-carotene, δ-carotene, γ-carotene and rubixanthin were detected in the partly-ripe and ripe fruits but not in the immature and mature-green samples. Phytofluene was observed in trace levels at all stages.