Objective: To determine the antipyretic effect of 100% Tamarindus indica (Tamarind) seed coat extract on the yeast-induced fever on Oryctolagus cuniculus (Male albino rabbits) Design: Experimental study design. Subjects: Twenty-four (24) male albino rabbits that had been examined by a veterinarian, were purposively selected based on the following criteria: male albino rabbit, weighing 1-2 kilograms, with initial temperature of not lower than 37ºC and not more than 40ºC, no physical deformities and those that had not been used in previous experiments. Procedures/Interventions: Twenty-four (24) male albino rabbits were randomly assigned into three groups namely the positive control group utilizing aspirin (15.16mg/kg), the negative control group using normal saline solution (1ml/kg) and the experimental group using 100% Tamarind seed coat extract (185.3mg/kg). These were placed in three separate cages. The weight of each rabbit was measured and recorded and its body marked with its assigned number for easy identification. The baseline body temperature for each rabbit was also obtained after one week of acclimatization, just before induction of fever. All the rabbits were then given subcutaneous injection of brewer yeast at a dose of 178mg/kg to induce fever. Their body temperature were recorded four hours after induction of fever for the next 3 hours at 30-minute intervals. The positive control group was given aspirin as treatment, the negative control group, normal saline solution and the test group Tamarind seed coat extract. All the treatments were administered orally. Research Instruments: A rectal thermometer was used in measuring body temperature. Data sheets were used to document all the data gathered. Results: The mean baseline temperature of the male albino rabbits prior to induction of fever was 39.53ºC for the experimental group, 39.43ºC for the positive control group and 39.15ºC for the negative control group. Four hours after the subcutaneous injection of Brewer's yeast, the mean baseline temperature of the experimental group was 40.65ºC, for positive group was 40.88ºC. The paired t-test showed that there was significant decrease in temperature starting 30 minutes post-treatment and for every measurement thereafter, in the positive group, after 1 hour in experimental group and after 2 hours in the negative group. The one-way Analysis of Variance (ANOVA) computed at 0.05 level of significance showed that there was no significant difference among the 3 groups' average temperatures at 30 minutes and at 1 hour and 30 minutes; and that there was a significant difference among the groups' temperature readings measured at 1 hour, 2 hour, 2 hours 30 minutes and 3 hours. The time intervals which showed significant difference were further tested using Duncan's Multiple Range Test. The test showed that there was no significant difference between the average temperatures of the experimental and positive groups and between the experimental and negative groups at 1 hour post-treatment whereas it showed a significant difference between experimental and positive groups and experimental and negative groups at 2 hours, 2hours and 30 minutes and 3 hours interval. This research has proven the efficacy of the Tamarind seed coat extract in lowering the temperature of the male albino rabbits with yeast-induced fever. Conclusion: The effect of the Tamarind seed coat extract was found to be similar with aspirin in the reduction of temperature of male albino rabbits with yeast-induced fever. However, the onset of effect of the seed coat extract was apparently only 2 hours after administration.