The changes in chemical, physical, and mechanical properties of fully matured coconut shell chars in relation to carbonization temperature (range: 400-950°C) and time (range: zero-3 h) have been studied. These properties were found to be more susceptible to carbonization temperature than to time. The results indicated an increase in fixed carbon content and true specific gravity of shell chars with rise of carbonization temperature and soak time. The majority of volatilization occurred up to about 800°C. The calorific value of shell char increased sharply with rise of carbonization temperature up to 600°C, and thereafter it decreased to 800°C. The porosity of shell char increased with increase of carbonization temperature up to 600°C followed by a decrease with further rise of temperature up to the range studied. Prolonged soaking at carbonization temperatures of 600, 800, and 950°C, in general, led to slight increases in the porosity and calorific values of resulting shell chars. The results showed that the crushing strength of shell char decreased markedly on increasing the preparation temperature up to 600°C, followed by an increase thereafter. An increase in soaking time at carbonization temperatures of 600, 800, and 950°C also influenced the shell char strength.