This study was conducted to determine relationship of the mammary glands size with milk production during the first lactation of Etawah Crossbreed/Peranakan Etawah (PE) goats at the Balai Besar Pembibitan Ternak Unggul Hijauan Pakan Ternak (BBPTU-HPT) Baturraden, Indonesia. The study used 41 first lactating PE goats. Variables in this study were taken by observation and measured of mammary glands. Data during the study which were taken included length, width, and circumference of udder, length, circumference, and distance between of teat, length and index of the mammary gland. Mammary gland index was calculated from the ratio between the length and circumference of the udder. Milk production was measured and recorded since the first day of lactation until day 91th. Data size of the mammary gland calculated the average and standard deviation. The data is then statistically analyzed regression. The results showed that milk production had a positive correlation with the circumference and length of the udder. Udder circumference correlation value to the milk production of 30.2%, while the length of the udder to the milk production of 22.3%. It was concluded that the production of goat's milk in the first lactation Etawah grade goat in BBPTU-HPT Baturraden correlated with the length and circumference of the udders but little correlation value.