The African monarch Akeem learns he has a long-lost son in the United States and must return to America to meet this unexpected heir and build a relationship with his son.

Three long, prosperous decades after Prince Akeem and Lisa McDowell's opulent wedding in Coming to America (1988), King Jaffe Joffer and Semmi, sensing that trouble is brewing in the African kingdom of Zamunda, drop a bombshell. As a result, with three lovely daughters and no sons, Prince Akeem's back is against the wall as General Izzi, the megalomaniac despot of the neighboring country of Nexdoria, dreams of seizing power through a political marriage of convenience. Now, newly-crowned King Akeem and his trusted confidante Semmi must return to where it all began, the bustling borough of Queens, New York, to retrieve Lavelle, the illegitimate son unsuspecting Akeem never knew existed. Can the prince of Zamunda restore peace and stability in less than a week?—Nick Riganas

On the 30th anniversary of his wedding with Lisa McDowell, Prince Akeem of Zamunda is summoned before his dying father, King Jaffe Joffer. Jaffe and his shaman Baba reveal to a baffled Akeem that he had sired a son during his first visit in Queens, New York, after his aide Semmi had enticed two women into spending the night with them while Akeem was still searching for his future queen. One of them inadvertently drugged Akeem, resulting in a tryst he did not remember. As Zamundian tradition demands that only a male successor can inherit the throne, and Akeem has fathered only daughters, Akeem is forced to travel back to Queens to retrieve his son. If not, Zamunda could face a hostile takeover by Zamunda's militaristic neighbor nation Nexdoria, whose dictator, General Izzi (the brother of Imani, Akeem's original arranged bride-to-be), has been pushing for Akeem's eldest daughter Meeka into marrying his foppish son, Idi.

Following King Jaffe's funeral and Akeem's ascension to king, he and Semmi travel back to Queens to find his illegitimate son. During a lighthearted reunion with the barbershop gang they bonded with, head barber Mr. Clarence informs them that the son in question is Lavelle Junson, a ticket scalper who hustles outside of Madison Square Garden. After an awkward reunion with Lavelle's mother Mary, Akeem takes them back to Zamunda, much to his family's displeasure. When General Izzi learns of this, he drops by to introduce his daughter Bopoto to Lavelle as a last shot at laying claim to the throne of Zamunda, but in order to qualify as a royal prince, Lavelle first has to pass a series of traditional - and hazardous - tests.

Lavelle is at first highly reluctant to place himself in danger, but then bonds with Mirembe, a royal groomer, who tells him of Akeem's quest to find his queen and encourages him to follow his own path. Lavelle then invites his uncle Reem, Mary's streetwise brother, to Zamunda who coaches him on how to blend his urban upbringing with his new royal status. Lavelle gradually develops an understanding with Akeem's family and, using his wits and some forced courage, he passes and is made Prince of Zamunda. However, at his accession party, Lavelle overhears a conversation between Akeem and Izzi which makes him believe that Akeem is just exploiting him, and he, Mirembe, Mary and Reem go back to New York. Upset at losing Mary, whom she has befriended, Lisa locks Akeem out of their bedroom. After a pep talk from his father-in-law Cleo, who reminds him of late Queen Aoleon's progressive mind, Akeem flies back to the States, while Semmi is left to stall Izzi, who intends to return the next day to either see Bopoto marry Lavelle or declare war.

Returning to Queens, Akeem finds that Lavelle and Mirembe are about to get married. Confronted by Lavelle and reminded of his own life story, he gives them his blessing and releases Lavelle from his marriage to Bopoto. When Mirembe expresses reluctance in the couple cutting all of their ties to Zamunda, Akeem offers to fly Mary's family back for a proper wedding. In the meantime, Semmi and the princesses, all trained staff fighters, fight off and subdue General Izzi when he invades the palace, forcing him to try a more diplomatic approach. Upon his return home, Akeem changes the royal succession by allowing his daughter Meeka to ascend to the throne upon his death, while Lavelle is made an ambassador to the United States, and General Izzi has opened Nexdoria for a peaceful political and trading relationship. The film concludes with a grand party at the royal palace to celebrate Lavelle and Mirembe's marriage, including the barbers from Queens as special guests and a performance of the song "We Are Family" from Sexual Chocolate.

(copied from Wikipedia)