The moisture content determination by direct methods is accurate, reliable, and can be done through an easy made and low cost equipment. This study was done to compare direct methods of moisture measurement. Three levels of seed moisture content (%) were used for dry bean (11,8, 13,8, 15,9), rice (13,4, 17,7, 22,7), and corn (13,9, 17,8, 26,2). The methods used for comparison were: oil destillation commonly known as pipoqueiro, and DUPEA - water equivalence; the 103°C/72h oven; and the 105°C/24h official reference oven method. The conditions of the experiment allow the following conclusions: a) the oil distillation method or ?pipoqueiro? is as confident as the oven methods; b) because it is fast and easy made method, the ?pipoqueiro? can be used for calibrating the eletronic moisture meters; e) the DUPEA methodology is mnot accurate for moisture determination of bean, rice and corn; d) another study is necessary to calibrate 103°C/72h with 105°C/24h oven methods.