Suramin, known for curing sleeping sickness and river blindness has been identified as a potent inhibitor of Nipah Virus (NiV) replication. At 100 µM, suramin completely abolishes the de novo RNA synthesis in NiV by binding within the NTP entry channel of the viral L protein, forming strong interactions with key conserved residues E291, K542, R551, K724, N833, and K893. By occupying this channel, the drug blocks the entry of nucleotide substrates into the active site, thereby preventing RNA synthesis n both biochemical assays and kidney cell–based systems.