| Dec 16, 1988 | First Southwest Bank | Eldorado | $9.8M | First State Bank&trust C |
| Dec 8, 1988 | First Bank & Trust Co. | Duncan | $42.0M | First Bank&trust Co |
| Dec 8, 1988 | Waukomis State Bank | Waukomis | $12.0M | Cimarron Bank |
| Nov 10, 1988 | Bank of the Northwest | Woodward | $19.5M | Bank of Woodward |
| Nov 10, 1988 | Miami National Bank | Miami | $9.2M | Bank of Miami |
| Nov 10, 1988 | The First National Bank of Gracemont | Gracemont | $6.6M | First State Bank |
| Oct 27, 1988 | Medical Center State Bank | Oklahoma City | $8.7M | American State Bank |
| Sep 29, 1988 | First State Bank | Seminole | $12.2M | First State Bank |
| Sep 22, 1988 | The First State Bank in Talihina | Talihina | $15.8M | Spiro State Bank |
| Sep 22, 1988 | The Security State Bank | Comanche | $9.0M | American National Bank |
| Sep 15, 1988 | Town & Country Bank | Bixby | $30.8M | Brookside State Bank |
| Sep 1, 1988 | American Bank of Muskogee | Muskogee | $28.6M | Citizens NB&T of Muskoge |
| Aug 31, 1988 | Frontier Savings & Loan | Ponca City | $1.03B | Commercial Fed BK a FSB |
| Aug 31, 1988 | Phoenix FS&LA | Muskogee | $419.4M | Cimarron FS&LA |
| Aug 31, 1988 | Home Savings Bank, F.A. | Lawton | $264.1M | Red River FS&LA |
| Aug 31, 1988 | Home S&LA | Bartlesville | $173.5M | Cimarron FS&LA |
| Aug 31, 1988 | Kingfisher FS&LA | Kingfisher | $124.4M | Chisholm |
| Aug 31, 1988 | First FS&LA | Elk City | $106.7M | Red River FS&LA |
| Aug 31, 1988 | Heritage S&LA | Elk City | $80.8M | Red River |
| Aug 31, 1988 | Peoples FS&LA | Ardmore | $49.9M | Red River FS&LA |
| Aug 18, 1988 | Citizens State Bank | Maud | $11.1M | Bank National Assn |
| Jul 29, 1988 | American of Anadarko | Anadarko | $65.1M | —
|
| Jul 21, 1988 | Union Bank & Trust | Bartlesville | $115.4M | First NB in Bartlesville |
| Jul 14, 1988 | The Security Bank | Warner | $9.4M | Vian State Bank |
| Jun 30, 1988 | Republic National Bank | Norman | $24.3M | Republic Bank of Norman |
| Apr 8, 1988 | First Federal of Shawnee | Shawnee | $130.7M | —
|
| Mar 31, 1988 | Union Bank & Trust Company | Oklahoma City | $182.5M | Union Bank&trust Co |
| Mar 25, 1988 | First National Bank of Del City | Del City | $30.9M | Lincoln National Bank |
| Mar 24, 1988 | Century Bank | Tulsa | $70.8M | Fourth NB of Tulsa |
| Mar 24, 1988 | Cashion Community Bank | Cashion | $6.7M | Community State Bank |
| Mar 10, 1988 | The First Nat Bank & Trust Co. of Cushing | Cushing | $60.3M | American NB of Bristow |
| Feb 18, 1988 | Mustang Community Bank | Mustang | $9.4M | First National Bank of M |
| Feb 11, 1988 | First State Bank | Oilton | $13.2M | American NB of Bristow |
| Jan 29, 1988 | Territory S&LA | Seminole | $31.2M | —
|
| Dec 3, 1987 | The Farmers National Bank of Cordell | Cordell | $62.3M | First NB of Weatherford |
| Nov 19, 1987 | Republic Bank | Oklahoma City | $49.1M | First NB in Bartlesville |
| Oct 8, 1987 | United Services Bank | Hartshorne | $15.3M | First NB&T Co of McAlest |
| Oct 8, 1987 | Citizens Bank of Krebs | Krebs | $14.7M | First NB&T Co of McAlest |
| Sep 24, 1987 | The Citizens Bank | Drumright | $35.1M | American NB of Bristow |
| Sep 17, 1987 | Mustang National Bank | Mustang | $12.1M | First National Bank of M |
| Sep 3, 1987 | The First National Bank of Tipton | Tipton | $8.2M | First National Bank in a |
| Sep 3, 1987 | The First National Bank of Hammon | Hammon | $6.3M | American National Bank |
| Aug 20, 1987 | American Exchange Bank & Trust Co | Norman | $87.8M | Bank of Oklahoma N.A. |
| Aug 20, 1987 | Sunbelt FS&LA | Watonga | $65.5M | Chisholm FS&LA |
| Aug 20, 1987 | The First State Bank | Willow | $6.7M | Guarantee State Bank |
| Aug 13, 1987 | First State Bank | Blanchard | $23.6M | First State Bank |
| Aug 13, 1987 | The First National Bank of Luther | Luther | $17.1M | First Wagoner Bank&trust |
| Aug 6, 1987 | Security State Bank | Roosevelt | $15.2M | First National Bank in a |
| Aug 6, 1987 | The Security State Bank | Davenport | $9.4M | First State Bank |
| Jul 30, 1987 | The First National Bank of Yukon | Yukon | $40.3M | Bank of Oklahoma N.A. |