Toxoplasmosis was diagnosed histologically in 9 kittens and 1 queen from 5 litters. In litter 1, four 3-month-old Siamese kittens and the queen were affected. The queen died of generalized toxoplasmosis, and her kittens died or were euthanatized 20, 22, or 28 days later. In litter 2, two of 3 Abyssinian 4- and 4.5-month-old kittens died of toxoplasmosis. In litter 3, an Abyssinian, delivered by cesarean section, became ill 17 days after delivery, and died 2 days later because of toxoplasmic hepatitis and pneumonia. In litter 4, three kittens, approximately 1 month old, were shedding Toxoplasma gondii-like oocysts, and the organism was identified histologically in tissues of 1 of them. In litter 5, one 3-week-old kitten out of 4 became ill. Toxoplasma gondii-like oocysts were found in feces and T gondii organisms were found in histologic sections of tissues. Toxoplasmosis was diagnosed histologically in 9 kittens and 1 queen from 5 litters. In litter 1, four 3-month-old Siamese kittens and the queen were affected. The queen died of generalized toxoplasmosis, and her kittens died or were euthanatized 20, 22, or 28 days later. In litter 2, two of 3 Abyssinian 4- and 4.5-month-old kittens died of toxoplasmosis. In litter 3, an Abyssinian, delivered by cesarean section, became ill 17 days after delivery, and died 2 days later because of toxoplasmic hepatitis and pneumonia. In litter 4, three kittens, approximately 1 month old, were shedding Toxoplasma gondii-like oocysts, and the organism was identified histologically in tissues of 1 of them. In litter 5, one 3-week-old kitten out of 4 became ill. Toxoplasma gondii-like oocysts were found in feces and T gondii organisms were found in histologic sections of tissues.