Porfirio Rubirosa was a “Latin lover” back in the days when the term suggested palm trees and romance instead of a “Saturday Night Live” sketch. And he was really quite skilled at his chosen craft. Between 1932 and his death in 1965, Rubirosa married five women, among them two American heiresses (Doris Duke and Barbara Hutton), two French actresses (Danielle Darrieux and Odile Rodin), and the daughter of one Latin American leader (Flor de Oro Trujillo).

Two things set Rubi apart in the race for pre-Hefner Playboy of the Year. The first he explained to the maitre d’ who was thrilled to find Rubi sitting with Aly Khan, Baby Pignatari, and Juan Capuro – “the four most famous playboys in the world” – right there in his restaurant: “But there is a difference between me and the other gentlemen,” Rubi told him. “They all pay their women, and all my women pay me!”

Rubi’s second distinction was the same as that of the porn-star hero of “Boogie Nights,” not to mention Milton Berle – and I don’t mean comedic timing. In “The Last Playboy: The High Life of Porfirio Rubirosa” (Fourth Estate, 356 pages, $24.95) Shawn Levy devotes a chapter titled “Yul Brynner in a Black Turtleneck” to Rubirosa’s legendary appendage. Rubi’s valet sold swatches of his boxer shorts as souvenirs. Ribald waiters called their establishment’s largest peppermill “the Rubirosa.” In the 1950s, when serious newspapers were busy with the House Un-American Committee, tabloids quoted songs referring to Rubirosa as a “Ding Dong Daddy.” I shudder to think what his nickname would have been were he a contemporary of Sir Mix-a-Lot.

Mr. Levy seems to have fallen into Rubi’s spell, dispensing tips on how to act like a playboy (“You had to be proficient in at least one sport”); explaining that Rubi was a favorite of the Kennedy family, except for “Bobby, the prig” (yes, Papa Joe was really much more fun than Bobby, when he wasn’t lobotomizing his children or mixing it up with organized crime figures); and relating breathlessly that Rubi became such a mythic figure that “one glamour gal got a shiner from her husband simply for chatting with him.”

But if he has soaked in Rubi’s aura (and he does evoke the mood of that swinging, wife-beating era very effectively), he doesn’t get inside Rubi’s mind. He never hazards a guess as to what (besides cold, hard cash) motivated Rubi to become such a lothario, or a puppet of the Trujillo regime, or a race car driver, or a jewel thief, or a Resistance fighter, among all the many things Rubi was rumored to be. We never get a sense of whether Rubi was ruthless or charming, amoral or empathetic, or a complicated combination of both. At times, he seems to exist simply as ballast to prop up the storied appendage, a man blessed or cursed with a little something extra and destined to live in interesting times (Latin American revolutions? Pre-war Germany? Rat Pack Las Vegas? Rubi was there).

In Mr. Levy’s defense, Rubi and many of his contemporaries have died, his two surviving wives were unavailable for comment, and even while alive, Rubi himself may not have been the most introspective of men. (I’m no doctor, but perhaps it was difficult to keep blood circulating to his head?).

At the end of the book, Mr. Levy does a fine job outlining Rubirosa’s significance to people who saw him as either a dictator’s pawn who betrayed his native Dominican Republic, or a barrier breaking civil rights icon. He quotes Langston Hughes as describing the mixed-race Rubirosa as “a colorful gentleman of color adding color and excitement, romance and the light touch to this rather grim world of wars, poverty and racism in which we live.” (Not that Rubi ever used that light touch to extend his hand in marriage to any woman who wasn’t white; it seems the gentleman preferred blondes in the mold of conquest Zsa Zsa Gabor.)

Were this discussion at the beginning of the book, rather than the end, the story of Rubirosa’s life may have seemed to have more weight. But for most of the book, Rubi comes across like a male precursor to Paris Hilton, someone famous for clothes, cash, and sexual exploits. It’s also not clear what makes him the last playboy – well-endowed, well-connected men align themselves with publicity-hungry women to this day. I don’t think Paris Latsis or Kevin Federline are in danger of seeking gainful employment anytime soon.

But comparison to the himbos of today does make Rubirosa’s allure clear. He spoke several languages, danced beautifully, was a good tipper, and, says one acquaintance, “Could hang on the words of a woman or man who spoke only banalities as if the very future of the world – and his future, especially – depended on these words.” Alliterative song titles aside, there was more to this man than his member.

Ms. Gage last wrote for these pages about Candace Bushnell.