Objectives: Delivering health care timely and geographically accessible are determining factors for the prognosis of children with cancer. This study analyzed geographic access and timeliness to diagnostic services in Colombia. Methods: In this Colombian national childhood cancer database-based study, patients and their diagnostic facilities were individually and separately space positioned. Distances between the household to the diagnostic facility, and between the clinical date of suspicion and diagnosis were determined. Using exploratory data analysis, we obtained a probability density function (lambda), which expressed a correlation percentage between the residential location of the patient and either travel time or timeliness of treatment. Results: 27 % of the sample of 731 patients had access to diagnostic centres in less than 30 min. The traveldistance to diagnostic centres was lowest in the Caribe and Andina Regions (43 % and 32 % distances up to 30 km respectively). However, in Amazonía and Orinoquía Regions, 87 % and 81 % had to travel more than 90 km – representing very long travel times. For more than 23 % of patients, time to diagnosis was more than 90 days, in Orinoquía, this was above 90 days for 1/3 of patients. Despite relatively short travel distances in the Caribe-Region, for 61 % time to diagnosis exceeded 30 days. Conclusions: This study identified clear shortcomings in the Colombian Health System related to the quality of childhood cancer-related health care in terms of timeliness, cancer networks, and geographic access. These inequities not only depend on sociodemographic-characteristics and should be intervened upon.