The potential complications related to unplanned conversion to thoracotomy remains a major concern in thoracoscopic lobectomy and may limit the wide adoption of this strategy. We reviewed the literature from 1990 until February 2022, analyzing all papers comparing successful thoracoscopic lobectomy versus converted thoracoscopic lobectomy and/or upfront thoracotomy lobectomy to establish whether unplanned conversion negatively affected outcomes. Thirteen studies provided the most applicable evidence to evaluate this issue. Conversion to thoracotomy was reported to occur in up to 23% of cases (range, 5%–16%). Vascular injury, calcified lymph nodes, and dense adhesions were the most common reasons for conversion. Converted thoracoscopic lobectomy compared to successful thoracoscopic lobectomy was associated with longer operative time and hospital stay in all studies, with higher postoperative complication rates in seven studies, and with higher perioperative mortality rates in four studies. No significant differences were found between converted thoracoscopic lobectomy and upfront thoracotomy lobectomy. Five studies evaluated long-term survival, and in all papers conversion did not prejudice survival. Surgeons should not fear unplanned conversion during thoracoscopic lobectomy, but to avoid unexpected conversion that may negatively impact surgical outcome, a careful selection of patients is recommended–especially for frail patients.