This paper examines the social and economic impacts of Mexican immigration on Fresno (California). Since the early 1980s, immigration to California has been dominated by illegal immigrants from rural Mexico seeking agricultural jobs in rural California. This rural migration impacts urban centers in agricultural regions; these impacts lag the dramatic and obvious effects on rural communities and are primarily the result of movement of second-generation immigrants to urban areas. Data for Fresno and Fresno County are presented on population growth and trends, ethnic composition, employment, unemployment, income, poverty rates, ethnic groups in the school population, limited English proficiency among students, and welfare recipients. Intensive family interviews with farmworkers who had received legalized status during 1986 immigration reforms found that few had moved into nonagricultural jobs, pursued formal education or other training, or acquired fluency in English. Their children, however, had enrolled in public schools, had learned English, and were moving to Fresno and other urban areas seeking nonfarm employment. Nevertheless, the second generation's odyssey to urban areas has been generally unsuccessful. It is suggested that the "Latinization" of rural central California has made assimilation unnecessary for Mexican immigrants, and this lack of assimilation negatively affects their children when they move to other areas. Recommendations are offered concerning immigration policy, educational needs, and development of nonagricultural employment opportunities. An appendix outlines Fresno County employment by sector, 1973-90. (SV)