In Terraria, how long does money you drop from death stay on the ground? I'm wondering if it is worth the risk of another death to try and run for my money.
Items dropped in Terraria Single-Player Mode do not disappear until picked up, destroyed, or until the game has been saved and exited. Coins, despite their monetary significance, are treated just the same as any other item in-game.
Items can only be destroyed (currently) by full immersion in Lava or Magma. Thus, as long as you didn't burn up in a magma pool, chances are good that your coins are still waiting there for you, even if it takes a bit of work to find.
I'm unsure how items are handled on multi-player servers.
I don't fully agree. I've seen that untaken blocks of dirt, stone etc. disappeared after some time. I think this behaviour is related to count of objects of same type on screen. But I didn't notice that money disappear. It looks like that they stay until you pick up them :-)
PS: It looks like I found the maximal count of objects of one type (NPCs, chests, collectable items and so on) in game. It may be 0x3e8 magic number or 1000 in decimal representation. It's very easy to confirm it. Take more than 4 stacks of blocks and begin to throw them away one by one. After that try to collect them back. If number of blocks will be lesser then before it means that items disappear.