Introduction The surgical treatment of complex spinal deformity and vertebral oncological diseases is becoming more common. The aim of this study was to prospectively record all the major complications observed in the perioperative and postoperative period for surgeries performed at our Division of Spine Surgery in the 2010 to 2012 period, correlating this score with different parameters to determine possible risk factors. Material and Methods A total of 285 surgeries were registered in 2010, 324 in 2011, and 308 in 2012. All the complications observed during the procedure and the follow-up period were recorded and classified according to the type (mechanical complications, neurological complications, infection, hematoma, cerebrospinal fluid fistula, systemic complications, and death related to the surgery). Results In 2010, on 285 surgeries 47 patients (16.5%) had 69 complications (24.2%): 25.7% for the treatment of oncological diseases, 23% for the treatment of degenerative diseases, 27% for the treatment of pathologies of traumatic origin, and 11% for the treatment of spondylodiscitis (infectious diseases). In 2011, on 324 surgeries 35 patients (10.8%) had 54 complications (16.7%): 16.3% for the treatment of oncological diseases, 16.3% for the treatment of degenerative diseases, 20% for the treatment of pathologies of traumatic origin, 28.6% for the treatment of spondylodiscitis. In 2012, on 308 surgeries, 25 patients (8.1%) had 36 complications (11.7%): 14.4% for the treatment of oncological diseases, 7.2% for the treatment of degenerative diseases, 16.7% for the treatment of pathologies of traumatic origin, and 20% for the treatment of spondylodiscitis. Conclusion On 917 spinal surgeries performed from January 2010 to December 2012, 159 complications (17.3%) were recorded, with a prevalence of mechanical complications and infections. The correlation of these complications with different parameters, such as age, sex, presence of comorbidities, previous spine surgery, type of surgery, will be analyzed to detect potential risk factors to be taken into consideration in the decision-making process for complex spinal surgery.