Since the City incorporated in 1989, it has experienced a significant level of growth. As of the census of 2000, Yucaipa had 41,207 residents, 15,193 households, and 10,680 families. The population density was 572.7/km² (1,483.4/mi²). There were 16,112 housing units at an average density of 223.9/km² (580.0/mi²). The racial makeup was 85.21% White, 0.90% African American, 1.08% Native American, 1.18% Asian, 0.13% Pacific Islander, 8.04% from other races, and 3.46% from two or more races. Hispanics or Latinos constitute 18.35% of the population.
There were 15,193 households out of which 35.4% had children under the age of 18; 54.2% were married couples; 11.6% had a female householder; and 29.7% were non-families. 25.3% of all households were made up of individuals and 13.4% of those were 65 years of age or older. The average household size was 2.67 and the average family size was 3.21.
The population was spread out with 28.5% under the age of 18, 7.6% from 18 to 24, 27.2% from 25 to 44, 21.2% from 45 to 64, and 15.5% who were 65 years of age or older. The median age was 37 years. For every 100 females there were 93.5 males. For every 100 females age 18 and over, there were 88.4 males.
The median income for a household in the city was $39,144, and the median income for a family was $48,683. Males had a median income of $40,480 versus $25,957 for females. The per capita income for the city was $18,949. About 8.8% of families and 11.2% of the population were below the poverty line, including 13.2% of those under age 18 and 7.2% of those age 65 or over.