Details on luffy's family and heritage, hasn't been revealed in either the manga or the anime, as of yet.
What's known so far is:
Luffy's adoptive brother - Portgas D. Ace
Luffy's father - Monkey D. Dragon
Luffy's Grandfather - Monkey D. Garp
However it has been theorized that Luffy's uncle is infact, Gol D. Roger, by the means of:
Roger being Garp's brother
Roger being Garp's son, thus Dragon's brother
Dragon marrying Roger's younger sister
Though none have been confirmed yet, it's been established that there is a clear connection between Roger and Luffy via the constant referals to their similarities throughout the anime/manga.
Plus, all theories suggest that Luffy and Ace are cousins, hence both the similarities in appearance and personality traits.
Monkey D. Dragon
it is unknown for luffys mother,BUT luffys father is known to be the revalutionary dragon who FREEKIN OWNS AN ISLAND TO HIMSELF,please dont ask the question of why that is lol
it can to a ciertain point. to stretch is one thing but to do Hone Fusen, is hard to attain
no it his uncleluffys dad is monkey d. dragon. he might be his uncle.Strong points that they may be related:Ace was adopted by the "monkey family" (luffy,dragon,garp)Ace is Gol D. Roger son, (not Gold Roger or Gold D. Roger)"Will of D"
Noodle's pet monkey MIKE!! :D
Monkey. D. Luffy, everyone in his family has a D as there middle name
Known characters, Monkey D. Luffy Monkey D. Dragon Monkey D. Garp Gol D. Roger Portgas D. Rouge Portgas D. Ace Jaguar D. Saul Marshall D. Teach. Trafalgar D. Water Law.
Monkey D. Luffy was created in 1997.
Flff ffd d d d d dd d d d d
Monkey D. Luffy , from the 'One Piece' anime series , is voiced by Colleen Clinkenbeard .
De Brazza's monkey
the monkey was alive on the 26th of agust 1996 :D x