EIO Eaton Vance Ohio Municipal Bond Fund Common Shared of Befeficial Interest, $.01 Par Value

Eaton Vance Insured Ohio Municipal Bond Fund (AMEX:EIO) (the "Fund"), a non-diversified closed-end investment company, today announced the earnings of the Fund for the six months ended March 31, 2006. The Fund's fiscal year ends on September 30, 2006. For the three months ended March 31, 2006, the Fund had net investment income of $614,156 ($0.245 per common share). From this amount, the Fund paid dividends on preferred shares of $158,130 equal to $0.063 for each common share), resulting in net investment income after the preferred dividends of $456,026, or $0.182 per common share. The Fund's net investment income for the six months ended March 31, 2006 was $1,229,988 ($0.490 per common share, before deduction of the preferred share dividends totaling $0.119 per common share), resulting in net investment income after the preferred dividends of $0.371 per common share. In comparison, for the three months ended March 31, 2005, the Fund had net investment income of $631,418 ($0.252 per common share). From this amount, the Fund paid dividends on preferred shares of $93,744 (equal to $0.038 for each common share), resulting in net investment income after the preferred dividends of $537,674, or $0.214 per common share. The Fund's net investment income for the six months ended March 31, 2005 was $1,282,575 ($0.511 per common share, before deduction of the preferred share dividends totaling $0.072 per common share), resulting in net investment income after the preferred dividends of $0.439 per common share. Net realized and unrealized gains for the three months ended March 31, 2006 were $499,621 ($0.191 per common share). Net realized and unrealized gains for the six months ended March 31, 2006 were $359,295 ($0.135 per common share). Net realized and unrealized losses for the three months ended March 31, 2005 were $298,460 ($0.109 per common share). The Fund's net realized and unrealized gains for the six months ended March 31, 2005 were $29,318 ($0.022 per common share). On March 31, 2006, net assets of the Fund applicable to common shares were $37,624,482. The net asset value per common share on March 31, 2006 was $14.97 based on 2,512,727 common shares outstanding. On March 31, 2005, net assets of the Fund applicable to common shares were $36,757,063. The net asset value per common share on March 31, 2005 was $14.64 based on 2,511,569 common shares outstanding. Common shares of the Fund are traded on the American Stock Exchange. The Fund is managed by Eaton Vance Management, a subsidiary of Eaton Vance Corp, which is listed on the New York Stock Exchange under the symbol EV. Eaton Vance and its affiliates had approximately $118.8 billion in assets under management on April 30, 2006. Eaton Vance Management will make available periodic summary information regarding portfolio investments. Those interested should call Eaton Vance at (617) 482-8260. -0- *T EATON VANCE INSURED OHIO MUNICIPAL BOND FUND SUMMARY OF RESULTS OF OPERATIONS (in thousands, except per share amounts) Three Months Six Ended Months Ended March 31, March 31, ----------------- ----------------- 2006 2005 2006 2005 -------- -------- -------- -------- Gross investment income $718 $742 $1,442 $1,498 Operating expenses ($104) ($111) ($212) ($215) -------- -------- -------- -------- Net investment income $614 $631 $1,230 $1,283 Net realized and unrealized gains (losses) on investments $499 ($298) $359 $29 Preferred dividend paid from net investment income ($158) ($94) ($300) ($180) Net increase (decrease) in net assets from operations $955 $239 $1,289 $1,132 ======== ======== ======== ======== Earnings per Share Outstanding ----------------------------------- Gross investment income $0.286 $0.296 $0.574 $0.597 Operating expenses ($0.041) ($0.044) ($0.084) ($0.086) -------- -------- -------- -------- Net investment income $0.245 $0.252 $0.490 $0.511 Net realized and unrealized gains (losses) on investments $0.191 ($0.109) $0.135 $0.022 Preferred dividend paid from net investment income ($0.063) ($0.038) ($0.119) ($0.072) -------- -------- -------- -------- Net increase (decrease) in net assets from operations $0.373 $0.105 $0.506 $0.461 ======== ======== ======== ======== Net investment income $0.245 $0.252 $0.490 $0.511 Preferred dividend paid from net investment income ($0.063) ($0.038) ($0.119) ($0.072) -------- -------- -------- -------- Net investment income after preferred dividend $0.182 $0.214 $0.371 $0.439 ======== ======== ======== ======== Net Asset Value at March 31, (Common Shares) ----------------------------------- Net assets (000) $37,624 $36,757 Shares outstanding (000) 2,513 2,512 Net asset value per share outstanding $14.97 $14.64 Market Value Summary (Common Shares) ----------------------------------- Market price on AMEX at March 31 $14.73 $14.98 High market price (six months ended March 31) $15.00 $16.60 Low market price (six months ended March 31) $13.71 $14.98 *T