Constructing a photocatalytic system for hydrogen generation is a promising means for producing clean and renewable energy. However, developing photocatalysts with high efficiency in a wide range of visible light is still a formidable challenge. Here, we report on a highly active system for photocatalytic hydrogen production from hydroiodic acid splitting that contains a soluble organic-inorganic hybrid PtIx/[(CH3)(2)NH2](3)[BiI6] as a newcomer photocatalyst for harvesting a wide range of visible light (up to 630 nm). Under irradiation at 465 nm, the photocatalytic system achieves apparent quantum yield of similar to 82.8% for photocatalytic hydrogen production along with a stable activity for at least 100 h. We propose that the superior photocatalytic performance is attributed to collisions between [BiI6](3)(-) and Pt ions (Pt2+ or Pt4+), giving rise to efficient charge separation, which could be an effective approach towards designing and fabricating organic-inorganic semiconductors with improved performance in photocatalysis.