Eriphyle persuaded Amphiaraus to take part in the Seven Against Thebes raid, though he knew he would die. She had been persuaded by Polynices, who offered her the necklace of Harmonia, daughter of Aphrodite. Amphiaraus reluctantly agreed to join the battle and asked his sons, Alcmaeon and Amphilochus to avenge his death. In the battle, Amphiaraus sought to flee from Poriclymenus, the son of Poseidon, who wanted to kill him, but Zeus threw his thunder and the earth opened to swallow Amphiaraus together with his chariot.
Alcmaeon killed his mother when Amphiaraus died. He was pursued by the Erinyes as he fled across Greece, eventually landing the court of King Phegeus, who gave him his daughter in marriage. Exhausted, Alcmaeon asked an oracle how to avoid the Erinyes and was told that he needed to stop where the sun was not shining when he killed his mother. That was the mouth of the river Achelous which had been silted up. The god of that river, also named Achelous, gave him his daughter, Callirhoe in marriage if Alcmaeon would retrieve the necklace and clothes which Eriphyle wore when she persuaded Amphiaraus to take part in the battle. Alcmaeon had given these jewels to Phegeus who had his sons kill Alcmaeon when he discovered Alcmaeon's plan.
In Oropos, Northwest of Attica, Amphiaraus was worshipped as a god. He was considered a healing and fortune-telling god and was associated with Asclepius. The healing and fortune-telling aspect of Amphiaraus came from him ancestry: he was related to the great seer Melampus. After making a sacrifice of a few coins, or sometimes a ram, at the temple, a petitioner slept inside and received a dream detailing the solution to his/her problem.