Objective: The lockdown precautions during the COVID-19 pandemic led to concerns about the delayed diagnosis of malignancies. This study aimed to compare the duration of complaints at home and the presence of metastasis at diagnosis during the pre-pandemic and pandemic period in children with cancer. Materials and Methods: All children diagnosed with cancer and followed up in our clinic between 2017 and 2022 were included. Patients with a diagnosis of acute/chronic leukemia were excluded. Age, gender, cancer type, duration of complaints, and presence of metastasis at diagnosis of the children were recorded. The duration of complaints and presence of metastasis at diagnosis were compared statistically before and after March 11, 2020, the start point of the COVID-19 pandemic in our country. Results: A total of 161 patients diagnosed with cancer were analyzed retrospectively; 61% of patients were males and 39% were females. These patients were diagnosed with brain tumors (23.6%), lymphomas (23%), neuroblastoma (13.7%), rhabdomyosarcomas (10.6%), Ewing’s sarcoma (4.3%), osteosarcoma (3.7%), Wilm's tumor (3.7%), and germ cell tumors (3.1%). The duration of complaint was longer during the pandemic than before the pandemic (median: 45 days vs. 30 days) ( P < .05). The presence of metastases at diagnosis was 45.3% in the pre-pandemic period, while it was 40% during the pandemic with no statistical difference ( P > .5). Conclusion: We concluded that the duration of complaint before diagnosis was longer during the pandemic, while this delay did not affect the metastasis rate at diagnosis in children with cancer. The high rates of distant metastases in newly diagnosed patients both before and during the pandemic suggest that more studies are needed to diagnose these patients earlier.