The effect of environmental factors on certain grain quality traits of three notified rice hybrids viz., PA 6201, PA 6444 and KRH-2 and one high-yielding inbred variety IR 64 were studied during wet seasons of 2005 and 2006 at two locations i.e. Simbhaoli and Hyderabad. Milling recovery and head rice recovery increased with increase in ageing from one month to six months and with increase in number of seedlings planted hill^-1 from 1 to 3. Further, these environmental factors like ageing and number of seedlings planted per hill had no or non-significant effect on chemical characters like amylose content, gelatinization temperature and aroma.