Immigration Amendments of 1988 - Amends the Immigration Reform and Control Act of 1986 to extend and provide for 15,000 additional visas in each of FY 1989 and 1990 for nationals of countries adversely affected by Public Law 89-236 (1965 immigration amendments). Directs the Secretary of State to use the existing list of qualified immigrants established under such Act.

Provides an additional 10,000 visas in each of FY 1990 and 1991 to immigrants from underrepresented countries. Defines "underrepresented country" as one whose natives have received less than 25 percent of the maximum immigrant visas available to it in FY 1988 (excluding admissions under the Public Law 89-236 program). Waives labor certification requirements for such immigrants.

Directs the Attorney General to extend through December 31, 1989, the H-1 visa status of certain registered nurses who have held such status for at least five years and whose status expires in 1988 or 1989, or expired in 1987 but is under request for administrative extension.

Immigration Amendments of 1988 - Amends the Immigration Reform and Control Act of 1986 to extend and provide for 15,000 additional visas in each of FY 1989 and 1990 for nationals of countries adversely affected by Public Law 89-236 (1965 immigration amendments). Directs the Secretary of State to use the existing list of qualified immigrants established under such Act.

Provides an additional 10,000 visas in each of FY 1990 and 1991 to immigrants from underrepresented countries. Defines "underrepresented country" as one whose natives have received less than 25 percent of the maximum immigrant visas available to it in FY 1988 (excluding admissions under the Public Law 89-236 program). Waives labor certification requirements for such immigrants.

Legal Immigration Amendments of 1988 - Amends the Immigration and Nationality Act to reduce quarterly and yearly levels of lawful immigration admissions.

Establishes a National Commission on Independent Immigration to review the impact of such independent admissions and recommend admissions levels based on labor market conditions and other economic factors. Requires an annual report to the President and to the appropriate congressional committees.

Establishes annual admission levels for independent immigrants at 150,000. Allocates such visas as follows: (1) one-third for members of the professions or persons with exceptional skills; (2) one-third for skilled or unskilled workers, investors, or retirees; and (3) one-third for persons chosen on a point system basis. Directs the Secretary of State, in consultation with the Attorney General and the Secretaries of Labor and Education, to establish such point system based on the following criteria: (1) age; (2) education; (3) occupational shortage; (4) additional skills; and (5) prearranged employment in a low unemployment area.

Amends petitioning procedure provisions to permit special immigrant petitions to be filed with the Attorney General.

Amends labor certification provisions to exclude certain classes of immigrants unless the Secretary of Labor certifies that there are not sufficient qualified U.S. workers and that employment of aliens in such positions will not adversely affect U.S. workers' wages and conditions. Directs the Secretary to conduct a study, and hold public hearings, about the labor certification process and to report to the appropriate congressional committees. Makes 800,000 additional immigrant visas available in FY 1990 through 1994 for spouses and children of legalized aliens.

Makes 200,000 additional second preference (spouses and unmarried sons and daughters of permanent residents) visas available for FY 1990 and 1991.

Extends through FY 1993 the program of additional visas (50,000 for FY 1989 through 1993) for nationals of countries adversely affected by Public Law 89-236 (1965 immigration amendments).