EXHIBIT 21.1

The following is a list of all of Pioneer Drilling Companys direct and indirect subsidiaries:



| | 1. | Pioneer Drilling Services, Ltd., a Texas corporation  100% direct subsidiary.
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| | 2. | Pioneer Global Holdings, Inc., a Delaware corporation  100% indirect subsidiary  100% owned by Pioneer Drilling Services, Ltd.
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| | 3. | Pioneer Services Holdings, L.L.C., a Delaware limited liability company  100% indirect subsidiary  100% owned by Pioneer Global Holdings, Inc.
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| | 4. | Pioneer Latina Group SDAD, Ltda., a Panama corporation  100% indirect subsidiary  owned by Pioneer Global Holdings, Inc. (99%) and Pioneer
Services Holdings, L.L.C. (1%).
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| | 5. | Pioneer de Colombia SDAD, Ltda., a Panama corporation  100% indirect subsidiary  owned by Pioneer Latina Group SDAD, Ltda. (99%) and Pioneer
Services Holdings, L.L.C. (1%).
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| | 6. | Pioneer de Colombia SDAD, Ltda., Surcusal Colombia, a Colombian branch  100% indirect subsidiary  100% owned by Pioneer de Colombia SDAD, Ltda.
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| | 7. | Pioneer Production Services, Inc., a Delaware corporation  100% direct subsidiary.
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| | 8. | Pioneer Wireline Services Holdings, Inc., a Delaware corporation  100% indirect subsidiary  100% owned by Pioneer Production Services, Inc.
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| | 9. | Pioneer Wireline Services, L.L.C., a Delaware limited liability company  100% indirect subsidiary  100% owned by Pioneer Wireline Services Holdings,
Inc.
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| | 10. | Pioneer Well Services, L.L.C., a Delaware limited liability company  100% indirect subsidiary  100% owned by Pioneer Production Services, Inc.
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| | 11. | Pioneer Fishing & Rental Services, L.L.C., a Delaware limited liability company  100% indirect subsidiary  100% owned by Pioneer Production
Services, Inc.
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