Data from the 1976 Survey of Income and Education are used to analyze the family income differentials among the five major Hispanic-American groups (Mexicans, Puerto Ricans, Cubans, Central and South Americans, and "other Spanish"), black non-Hispanics, and white non-Hispanics. Total family income is first classified by its four major sources: earnings of a male head, earnings of a wife or female head, earnings of other family members, and property or transfer income. Next, each potential source of intergroup differences is analyzed for male earnings and then for female earnings: differences in family structure, labor force participation, weeks employed, hours worked per week, and wage rates, For each factor, the ratio of each minority group's average value to that of white non-Hispanics is computed to determine where the overall income gaps arise. In order to adjust for group differences in demographic composition, Fisher's ideal index is also computed for the factors exhibiting sizable gaps.