The use of rainwater is a reliable alternative to reducing clean water consumption and water bills. This study assessed Haitians’ willingness to invest in rainwater infrastructure (RWI). A questionnaire with closed and open-ended questions was used for this purpose. For closed-ended questions, ‘0’ and ‘1’ were used for negative and positive answers, respectively. Other numbers were used to encode the open-ended questions. The two-tailed Z-test was used to compare two proportions, where a result was statistically significant when the p-value was superior to 0.05. Of 362 rainwater users, 81.2% were used to using it for washing, bathing, cooking, flushing, and drinking. About 73.4% of households with 1–3 people, compared with 84.0% of families with 4–6 people, used rainwater. Of all the respondents, 82.3% would invest in RWI whether the government accepts to finance such a project up to 50.0%. More than 73.0% of respondents in each locality would invest in rainwater in RWI under the conditions previously mentioned. It is concluded that the implementation of RWI and decentralization of water systems are well seen by the rainwater users in Haiti, but the unwillingness of the Haitian government could be the main barrier to such a transition.