Synopsis for
Last Woman on Earth (1960) More at IMDbPro »

A rich man Harold Gern (Antony Carbone), busy with making money and spending it just as fast, is newly married with Evelyn (Betsy Jones-Moreland) and on his honeymoon in Puerto Rico. His lawyer MArtin Joyce (Robert Towne as Edward Wain) is there too on business to try and get him out of a situation with the government. Harold ganbles a lot and one day decide to deal with the lawyer by going fishing and scooba diving.

The three go underwater fishing and after a small accident with a speargun, they all come up to the boat. When they remove their air apparatus, they can't breath. Keeping the air tanks, they go back to shore to find help. As they cross the jungle to get to town quicker, they run out of air, but they realize plants give out oxygen and they are able to breath once again. They discover that everyone, even animals, are all dead.

To avoid the stink and disease, they move a villa on the corner of the island and begin to make the best of things there. They plan to eventually move to a colder place like northern Canada to avoid pests like ants, that managed to survive.

There is only one women and they are two men. Tension and the need for a woman begin to effect the two men and eventually they get into a fight. Halrold hits Martin onthe head first with a rock and later with the butt of a gun. The concussion is more than what Martin can take and he eventually dies. Harold and Eve are the only ones left in the world.