Marimar es una joven inocente que vive con sus abuelos en una chosa en la playa. Son muy pobres y a veces Marimar tiene que ir a robar para dar a su familia de que comer. Un dia se encuentra necesitada y va a la Hacienda Ibañez para robar unas verduras y huevos para que sus abuelos no mueran de hambre, pero el capataz de la hacienda la descubre. Este malechor decide de aprovecharse de ella; le dice que puede tomar las verduras si ella le da un beso. Ella resiste y sus gritos trae corriendo a Sergio, el hijo consentido de la casa grande. Sergio la proteje y le dice que de bajo de toda su mugre, ella es "bella." Marimar se enamora de el en ese mismo instante. Y cuando Sergio quiere desquitarse con su familia porque no quieren darle su parte de la herencia y lo piden que siente cabeza, el concibe un plan para casarse con "la mugrosa de la playa" y asi humillarlos. Marimar, deslumbrada, acepta casarse con Sergio y cae en su red sin saber que su propio padre, un hombre muy rico que abandonó a su mamá, la esta buscando para que ella sea su heredera.

Marimar is an innocent girl who lives on the beach with her elderly grandparents. They are very poor, and sometimes, Marimar has to steal to keep food on the table. One day she finds herself in need and she goes to the Hacienda Ibanez to steal some vegetables and eggs for her family. The foreman catches her redhanded and attempts to take advantage of her; he tells her that she can take the vegetables if she lets him kiss her. Marimar resists and her screams bring Sergio, the spoiled son of the house, running. He defends her and then tells her that under all her grime she is "beautiful." Marimar falls in love with him on the spot. And when Sergio hatches a plot to revenge himself on his family because they won't give him his half of the inheritance, insisting that he settle down once and for all, he concieves of a plan to marry the "dirty girl from the beach" to humiliate them. Marimar, dazzled, agrees to marry Sergio and falls into his fiendish plot . . .without knowing that her own father, an extremely wealthy man who abandoned her mother, is looking for her now to make her his heir.