Objective The aim of this clinical retrospective study was to describe the postoperative complications and associated factors of double pelvic osteotomy (DPO) using DPO plates. Materials and Methods Medical records were searched for dogs that underwent unilateral or bilateral DPO using DPO plates from February 2009 to October 2018 and were re-evaluated for a minimum of 1 to 2 months postoperatively. A variety of commercially available, specific DPO plates were used. Complications were determined during the immediate postoperative period and at the time of the clinical and radiographic re-evaluations done 1 and/or 2 months postoperatively. Results A total of 458 DPO (226 right, 232 left) performed in 305 dogs satisfied the inclusion criteria. Double pelvic osteotomy plates from eight different manufacturers were used: Fixin (n = 160), Kyon (n = 154), New Generation Device (n = 63), Hofmann (n = 61), Veterinary Instrumentation (n = 12), DePuy Synthes (n = 4), Porte (n = 3) and Koenigsee (n = 1). Mean age of the dogs was 6.2 months (range: 5–8 months), and the body weight ranged from 10 to 47 kg. Overall, a total of 42 complications occurred in 38 DPO (8.2%). Complications included greenstick fracture of the ischium in 14 DPO (3%), isolated screw loosening in 13 DPO involving 16 of a total of 2,947 screws (0.5%), isolated screw breakage in 4 DPO involving 5 of 2,947 screws (0.1%), incomplete ilium fracture in 3 DPO (0.6%), partial caudal plate avulsion in 3 DPO (0.6%), iatrogenic sciatic neuropraxia in two DPO (0.4%), suspected surgical site infection (SSI) in 1 DPO (0.2%) and persistent pain and lameness caused by the implant in 2 DPO (0.4%). The case of suspected SSI and the two cases of persistent pain were classified as major complications (3 DPO, 0.6%), requiring medical and surgical intervention, respectively, whereas other 39 complications in 35 DPO were classified as minor, not requiring treatment (7.6%). Conclusion Double pelvic osteotomy using DPO plates appears to be a safe surgical option for the treatment of hip dysplasia in growing dogs; no catastrophic complications were reported and the incidence of complications (0.6% major complications and 7.6% minor complications) was low. This study showed that DPO using DPO plates and proper technique was safe in 92% of cases. The only two factors found to be significantly associated with the development of complications after DPO were the laterality (left-sided or right-sided) and body weight.