The aim of the present study was to follow the time related developmental changes of caprine foetuses to aid in their age determination. Certain gross external features along with body size changes were studied. Twenty five pregnant Sahel does of known gestational age managed under controlled conditions were used for the study. Absolute changes in the body weight, crown-rump length and height at withers and their relative growth changes compared to body size had similar and significant growth relationships. All the parameters showed high positive significant correlation with the foetal age and with each other with r-values ranging from 0.975 to 0.998. A chronological guide on age estimation of caprine foetuses at 28 day gestational interval, evolved from observations based on developmental horizons. The present study has provided a baseline data which could be applied for age estimation of Sahel goat foetuses. It has also indicated that, it is necessary to employ many criteria involving physiological horizons to estimate the age of a foetus age within narrow limits.