. The objective of the study was to determine the iodine status and to map the thyroxin hormone concentration in etawah crossbred goat (ECG) at different physiological stages and its interrelation to the nutrition and performance. Fifteen female ECG was allotted in three physiolgical stage groups: female kid, young female goat and lactating goat, fed elephant grass and tofu byproduct. The study was conducted in Tossa Shakti Agro Company (TSA), Central Java, Indonesia. Analysis of variance in completely randomized design was used to determine the effect of physiological stages on soil and feed iodine content, blood serum thyroxin hormone concentration, nutrient and feed dry matter consumption, average daily gain and milk production. Result showed that soil iodine content was adequate to stimulate plant growth (3.109 mg/kg). Consumed feed iodine content was adequate to all physiological stages, female kid, young female and lactating goat (1.003; 0.940 and 0.820 mg/kg, respectively). Thyroxin hormone concentration in blood serum of female kid and young female goat was in normal range (8.23 and 10.05 µg/dl) but the concentration of thyroxin hormone in blood serum of lactating goat was marginal ( 6.17 µg/dl). Iodine supplementation was required for lactating etawa crossbred goat if tofu byproduct was included in its ration.