ObjectivesLittle is known regarding how natural disasters affect patients with cancer in low-income and middle-income countries. The objective of the present study was to assess the impact of the 2015 Nepal earthquake on the admission of patients with cancer at a core medical institution in Kathmandu.Design, setting and participantsWe considered all 3520 cancer patient admissions to Tribhuvan University Teaching Hospital, from 25 April 2013 to 24 April 2017 (2 years before and 2 years after the earthquake).Outcome measuresThe number of cancer patient admissions was calculated for each month. Using a negative binomial model, we estimated the incidence rate ratio (IRR) for admission numbers each month after the earthquake compared with the pre-earthquake baseline and investigated chronological change.ResultsThe total admission number in the first month after the earthquake was decreased compared with that of the predisaster baseline (IRR=0.66, 95% CI 0.43 to 1.00), which largely reflected decreased admissions of patients from outside of the most disaster-affected districts. From the second month, the admission number consistently exceeded the predisaster baseline for the remaining postdisaster period. In contrast to the month of the disaster, the continuation of increased admissions was most prominent among those from outside of the most affected districts.ConclusionsAfter a transient decrease immediately following the 2015 Nepal earthquake, there was a long-term increase in cancer patient admissions in a core hospital in Kathmandu. These changes were seen most prominently in patients from outside the most disaster affected areas.