Saudi Arabia has ordered Lebanon's ambassador to leave within 48 hours over "insulting" comments by a Lebanese minister.
The kingdom has also imposed a blanket ban on all imports from Lebanon.
The move comes days after remarks by Lebanon's information minister about the Saudi-led military campaign in Yemen sparked outrage in the kingdom.
The United Arab Emirates (UAE), Bahrain and Kuwait followed suit with diplomatic action on Saturday.
The Arab League said on Saturday it was concerned about the deteriorating relations, and urged Gulf countries "to reflect on the measures proposed to be taken... in order to avoid further negative effects on the collapsing Lebanese economy".
The row broke out after an interview aired earlier this week showing Lebanon's Information Minister George Kordahi appearing to call Saudi Arabia and the UAE aggressors in the war in Yemen.