Purpose: Post-thoracotomy pain syndrome (PTPS) and chronic postsurgical neuropathic pain (CPNP) were evaluated 4 months after thoracic surgery whether the approach was a posterolateral (PL) incision or the less invasive axillary (AX) one. Methods: Patients, 79 in each group, undergoing a thoracotomy between July 2014 and November 2015 were analyzed 4 months after surgery in this prospective monocentric cohort study. Results: More PL patients suffered PTPS (60.8% vs. 40.5%; p = 0.017) but CPNP was equally present (45.8% and 46.9% in the PL and AX groups). Patients with PTPS have more limited daily activities (p < 0.001) but a similar psychological disability (i.e., catastrophism). Patients with CPNP have an even greater limitation of daily activities (p = 0.007) and more catastrophism (p = 0.0002). Intensity of pain during mobilization of the homolateral shoulder at postoperative day 6 (OR = 1.40, CI 95% [1.13-1.75], p = 0.002); age (OR = 0.97 [0.94-1.00], p = 0.022), and presence of pain before surgery (OR = 2.22 [1.00-4.92], p = 0.049) are related to the occurrence of PTPS; while, height of hypoesthesia area on the breast line measured 6 days after surgery is the only factor related to that of CPNP (OR = 1.14 [1.01-1.30], p = 0.036). Conclusion: Minimally invasive surgery was associated with less frequent PTPS, but with equal risk of CPNP. Pain before surgery and its postoperative intensity are associated with PTPS. This must lead to a more aggressive care of pain patients before surgery and of a better management of postoperative pain. CPNP can be forecasted according to the early postoperative height of hypoesthesia area on the breast line.