BACKRGOUND: Good progress is being made towards universal access to contraceptives, however stock-outs still jeopardize progress. A seldom considered but important building block in optimizing supply management is the degree to which health workers feel motivated and responsible for monitoring supply. We explored how and to what extent motivation can be improved, and the impact this can have on avoiding stock-outs. METHODS: Fifteen health facilities in Maputo Province, Mozambique, were divided into 3 groups (2 intervention groups and 1 control), and 10 monthly audits were implemented in each of these 15 facilities to collect data through examination of stock cards and stock-counts of 6 contraceptives. Based on these audits, the 2 intervention groups received a monthly evaluation report reflecting the quality of their supply management. One of these 2 groups was also awarded material incentives conditional on their performance. A Wilcoxon-Mann Whitney test was used to detect differences between the groups in the average number of stocked-out centres, while changes over time were verified through applying a Friedman test. Additionally, staff motivation was measured through interviewing health care providers of all centres at baseline, and after 5 and 10 months. To detect differences between the groups and changes over time, a Kruskal Wallis and a Wilcoxon signed-rank test were applied, respectively. RESULTS: Motivation reported by providers (n = 55, n = 40 and n = 39 at baseline, 1st and 2nd follow-up respectively) was high in all groups, during all rounds, and did not change over time. Facilities in the intervention groups had better supply management results (including less stock-outs) during the entire intervention period compared with those in the control group, but the difference was only significant for the group receiving both material incentives and a monthly evaluation. However, our data also suggest that supply management also improved in control facilities, receiving only a monthly audit. During this study, more stock-outs occurred for family planning methods with lower demand, but the number of stock-outs per family planning method in the intervention groups was only significantly lower, compared with the control group, for female condoms. CONCLUSIONS: While a rise in motivation was not measurable, stock management was enhanced possibly as a result of the monthly audits. This activity was primarily for data collection, but was described as motivating and supportive, indicating the importance of feedback on health workers' accomplishments. More research is needed to quantify the additional impact of the interventions (distribution of evaluation reports and material incentives) on staff motivation and supply management. Special attention should be paid to supply management of less frequently used contraceptive methods.