An interest rate cut by the European Central Bank during the month did little to improve sentiment among Irish consumers.
The KBC Bank/ESRI consumer sentiment index rose slightly in May to 61.2 from 58.9 in April.
KBC Bank said sentiment had not changed significantly over the past three months as "consumers await decisive evidence indicators as to whether recovery is taking hold or greater difficulties might lie ahead.
The most positive element of the May survey of consumers was in relation to the outlook for their household finances.
This is one of five areas a sample of Irish consumers are asked about each month in order to compile the index.
KBC cautioned, however that, a limited improvement in May did not alter "the general picture of an Irish consumer who remains worried about a continuing deterioration in their financial situation".
The May results show that only 10% of those surveyed see an improvement in their personal financial situation in the coming year compared to 56% who see a further weakening.
In April just 7% said they saw prospects of improvement compared to 60% who saw further weakening.