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

Eaton Vance Insured Ohio Municipal Bond Fund (AMEX:EIO), a non-diversified closed-end investment company, today announced the earnings of the Fund for the three and nine-month periods ended June 30, 2005. The Fund's fiscal year ends on September 30, 2005. For the three months ended June 30, 2005, the Fund had net investment income of $622,842 ($0.248 per common share). From this amount, the Fund paid dividends on preferred shares of $130,590 (equal to $0.052 for each common share), resulting in net investment income after the preferred dividends of $492,252, or $0.196 per common share. The Fund's net investment income for the nine months ended June 30, 2005 increased to $1,905,417 ($0.759 per common share, before deduction of the preferred share dividends totaling $0.124 per common share), resulting in net investment income after the preferred dividends of $0.635 per common share. In comparison, for the three months ended June 30, 2004, the Fund had net investment income of $663,819 ($0.265 per common share). From this amount, the Fund paid dividends on preferred shares of $57,305 (equal to $0.023 for each common share), resulting in net investment income after the preferred dividends of $606,514, or $0.242 per common share. The Fund's net investment income for the nine months ended June 2004 increased to $1,983,372 ($0.792 per common share, before deduction of the preferred share dividends totaling $0.061 per common share), resulting in net investment income after the preferred dividends of $0.731 per common share. Net realized and unrealized gains for the three months ended June 30, 2005 were $1,014,426 ($0.394 per common share). The Fund's net realized and unrealized gains for the nine months ended June 30, 2005 were $1,043,744 ($0.416 per common share). In comparison, net realized and unrealized losses for the three months ended June 30, 2004 were $2,051,555 ($0.821 per common share). The Fund's net realized and unrealized losses for the nine months ended June 30, 2004 were $1,951,431 ($0.779 per common share). On June 30, 2005, net assets of the Fund applicable to common shares were $37,725,304. The net asset value per common share on June 30, 2005 was $15.02 based on 2,512,182 common shares outstanding. In comparison, on June 30, 2004, net assets of the Fund applicable to common shares were $34,699,307. The net asset value per common share on June 30, 2004 was $13.84 based on 2,507,482 common shares outstanding. Common shares of the Fund are traded on the American Stock Exchange. The Fund is managed by Eaton Vance Management. Eaton Vance and its affiliates had $106 billion in assets under management on July 31, 2005. 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 Nine Months Ended Ended June 30, June 30, ----------------- ----------------- 2005 2004 2005 2004 -------- -------- -------- -------- Gross investment income $729 $765 $2,226 $2,295 Operating expenses (106) (101) (321) (312) -------- -------- -------- -------- Net investment income $623 $664 $1,905 $1,983 Net realized and unrealized gains (losses) on investments $1,014 ($2,052) $1,044 ($1,951) Preferred dividends paid from net investment income ($131) ($57) ($311) ($153) Preferred dividends paid from net realized gains $0 $0 $0 ($7) -------- -------- -------- -------- Net increase (decrease) in net assets from operations $1,506 ($1,445) $2,638 ($128) ======== ======== ======== ======== Earnings per Common Share Outstanding ----------------------------------- Gross investment income $0.290 $0.305 $0.887 $0.916 Operating expenses (0.042) (0.040) (0.128) (0.124) -------- -------- -------- -------- Net investment income $0.248 $0.265 $0.759 $0.792 Net realized and unrealized gains (losses) on investments $0.394 ($0.821) $0.416 ($0.779) Preferred dividends paid from net investment income ($0.052) ($0.023) ($0.124) ($0.061) Preferred dividends paid from net realized gains $0.000 $0.000 $0.000 ($0.003) -------- -------- -------- -------- Net increase (decrease) in net assets from operations $0.590 ($0.579) $1.051 ($0.051) ======== ======== ======== ======== Net investment income $0.248 $0.265 $0.759 $0.792 Preferred dividends paid from net investment income (0.052) (0.023) (0.124) (0.061) -------- -------- -------- -------- Net investment income after preferred dividends $0.196 $0.242 $0.635 $0.731 ======== ======== ======== ======== Net Asset Value at June 30 (Common Shares) ----------------------------------- Net assets (000) $37,725 $34,699 Shares outstanding (000) 2,512 2,507 Net asset value per share outstanding $15.02 $13.84 Market Value Summary (Common Shares) ----------------------------------- Market price on AMEX at June 30 $16.20 $14.10 High market price (nine months ended June 30) $16.60 $16.40 Low market price (nine months ended June 30) $14.75 $13.27 *T