Since 2015, the Zambia National Malaria Elimination Centre has conducted routine data quality audits in Central, Southern, and Western provinces, but trends in data reporting accuracy have not been examined. Routine data quality audit data collected at health facilities reporting into the monthly health management information system (HMIS) and weekly malaria rapid reporting system (MRRS) were used to measure data reporting accuracy trends from 2015 to 2022 and potential influencing factors using three data elements: outpatient department attendance and rapid diagnostic test (RDT)-tested cases for HMIS and MRRS, total confirmed cases for HMIS only, and RDT-positive cases for MRRS only. Reporting accuracies for HMIS and MRRS data elements and the percentage of facilities reporting with high accuracy (≥85%) improved over this period. Low-accuracy (<70%) health facilities were uncommon, accounting for less than 15% of facilities for HMIS and MRRS. With each successive DQA visit, the proportion of facilities with high accuracy increased from visits 1 to 8: 23% to 56% (HMIS) and 42% to 85% (MRRS). No correlation was observed between facility size or incidence and overall accuracy for HMIS and MRRS. Starting in 2017, about 40-50% of health facilities appeared to be overreporting incidence in comparison with their register-based incidence. The risk stratification determined by register-based and reported incidences matched in more than 70% of facilities. Routine data quality audits conducted between 2015 and 2022 in Central, Southern, and Western provinces showed an improvement in malaria data reporting accuracy.