Background: Minimally invasive surgery (MIS) is an accepted surgical technique for the treatment of a variety of benign diseases. Presently, the use of MIS in patients with cancer is progressing. However, the role of MIS in children with solid neoplasms is less clear than it is in adults. Although the use of diagnostic MIS to obtain biopsy specimens for pathology is accepted in paediatric surgical oncology, there is limited evidence to support the use of MIS for the resection of malignancies. This review is the second update of a previously published Cochrane review. Objectives: To ascertain differences in outcome between the minimally invasive and open surgical approaches for the treatment of solid intra-abdominal or intra-thoracic neoplasms in children. The primary outcomes of interest are OS, EFS, port-site metastases and recurrence rate; the secondary outcome of interest is surgical morbidity. Search methods: We searched CENTRAL (The Cochrane Library 2014, Issue 1), MEDLINE/PubMed (from 1966 to February 2014) and EMBASE/Ovid (from 1980 to February 2014) to identify relevant studies. In addition, we searched reference lists of relevant articles and reviews and the conference proceedings of the International Society for Paediatric Oncology and the American Society of Clinical Oncology from 2003 to 2013. On 1 May 2014 we scanned the ISRCTN Register (on www.controlled-trials.com), the National Institutes of Health register (on www.controlled-trials.com and www.clinicaltrials.gov) and the World Health Organization International Clinical Trials Registry Platform (on www.apps.who.int/trialsearch) for ongoing trials. Selection criteria: Randomised controlled trials (RCTs) or controlled clinical trials (CCTs) comparing MIS to open surgery for the treatment of solid intra-thoracic or intra-abdominal neoplasms in children (aged 0 to 18 years) were considered for inclusion. Data collection and analysis: Two authors performed the study selection independently. Main results: The literature search retrieved 542 references. After screening the titles and abstracts we excluded 534 references which clearly did not meet the inclusion criteria. We assessed eight full text studies for eligibility and all of these studies were excluded from the review because they were not RCTs or CCTs. These excluded studies included case series, retrospective chart reviews and retrospective cohort studies. The scanning of reference lists and conference proceedings did not identify any additional studies and no (ongoing trials) were identified by the searches of trial registries. No studies that met the inclusion criteria of this review were identified Authors' conclusions: No RCTs or CCTs evaluating MIS for the treatment of solid intra-thoracic or intra-abdominal neoplasms in children could be identified. The current evidence base informing the use of MIS in children with solid abdominal and thoracic neoplasms is based on other study designs like case reports, retrospective chart reviews and cohort studies and should be interpreted with caution. Thus there is insufficient evidence to allow any definitive conclusions regarding the use of MIS in these patients. High quality RCTs comparing MIS to open surgery are required. To accomplish this, centres specialising in MIS in children should collaborate.