The objective of this study was to determine the inheritance mechanisms of panicle type of Brazilian oat genotypes. Two experiments with the fixed genotypes UFRGS 884087 and UFRGS 871547 and with the segregating population (F2 and F3) derived from the cross between these two genotypes, using a complete ramdomized block experimental design with two replications, were carried out in the field in 1989 and 1990. The results obtained from individual F2 plants and from F3 progenies were grouped and the frequencies were distributed by X2 analysis, after adjusting them to models invovling several gene number. Compact panicle type was controlled by a major gene having additive effect; this gene is linked to the one conditioning short plant stature in the genotype UFRGS 884087.