Feral cats are widespread in the countryside of Majorca (Balearic Islands, Spain). Since they are not subject of sanitary control, they can act as reservoir of parasites of veterinary and zoonotic interest. The main organs of 58 wild-trapped cats in 16 different areas from Majorca were analyzed by helminths. All the cats were parasitized, and eight species of helminths were retrieved (mean = 3.4 species per cat, with 74% of the cats harboring three or more species). Seven of them presented a prevalence >20%: Joyeuxiella pasqualei (76%), Diplopylidium acanthotetra (60%), Dipylidium carracidoi (33%), Taenia taeniaeformis (22%), Ancylostoma tubaeforme (91%), and Toxocara cati (35%) in the gastrointestinal tract, and Oslerus rostratus (24%) in lungs. The A. tubaeforme prevalence and intensity (mean = 30, up to 396) is the highest recorded for a population of cats. Prevalence and abundance of J. pasqualei and D. acanthotetra were strongly associated, secondary to the use of the same intermediary host (geckos). Other positive associations found are probably related to host susceptibility. Abundance of D. acanthotetra, T. cati, and A. tubaeforme and the number of species per host were negatively correlated with cat body condition (assessed by the kidney fat index). Females were more frequently parasitized by A. tubaeforme than males, and adult females were more heavily infested by J. pasqualei and D. acanthotetra than cats from other groups. These and other findings are discussed in relation with host ecology. Feral cats serve as reservoirs of helminths in the countryside of Majorca and their populations should be controlled.