CERTIFICATIONS PURSUANT TO SECTION 906
EX-99.906CERT
CERTIFICATION
R. Jay Gerken, Chief Executive Officer, and Robert J. Brault, Chief Financial Officer of High Income Opportunity Fund Inc.; (the "Registrant"), each certify to the best of his knowledge that:
1. The Registrant's periodic report on Form N-CSR for the period ended March 31, 2006 (the "Form N-CSR") fully complies with the requirements of section 15(d) of the Securities Exchange Act of 1934, as amended; and
2. The information contained in the Form N-CSR fairly presents, in all material respects, the financial condition and results of operations of the Registrant.
| Chief Executive Officer | Chief Financial Officer |
| High Income Opportunity Fund Inc. | High Income Opportunity Fund Inc. |
/s/ R. Jay Gerken | /s/ Robert J. Brault |
| R. Jay Gerken | Robert J. Brault |
| Date: June 8, 2006 | Date: June 8, 2006 |
This certification is being furnished to the Securities and Exchange Commission solely pursuant to 18 U.S.C. §1350 and is not being filed as part of the Form N-CSR with the Commission.