New figures show that the volume of retail sales fell by 0.8% in October compared to September on the back of falls in the sales of electrical goods and fuel.
However, the Central Statistics Office said that on an annual basis, the volume of retail sales rose by 6.9%.
The CSO said that when car sales are excluded, retail sales were down by 0.3% in the month while there was an annual increase of 5.8%.
On a monthly basis, furniture and lighting sales rose by 3.8%, while bar sales increased by 2.1% and sales in department stores were up 1.4%.
Sales of electrical goods decreased by 2.9%, while fuel sales eased by 2.1% and hardware paint and glass sales were down 1.3%, the CSO added.
Today's figures also show a decrease of 1% in the value of retail sales in October compared to September, while there was an annual increase of 3.5% compared to the same time last year.
When car sales are excluded, there was no change in the value of retail sales on a monthly basis and an annual increase of 2.4%.
Commenting on today's weaker than expected figures, Merrion economist Alan McQuaid said that although retail sales remain erratic on a monthly basis, the underlying trend is positive.
"While most attention has been on cars, personal spending in other areas is picking up too and is becoming more broad-based. This can only be good news for retailers and employment prospects in the sector," he said.
The economist said that after the recent tax reductions announced in Budget 2016, he thinks that next year will see an even better performance and the biggest rise in personal spending since the "Celtic Tiger" era.
Davy economist David McNamara said that it remains to be seen what impact the advertising blitz surrounding "Black Friday" will have on the November figures but, overall, 2015 looks set to be the best year for the retail sector since 2008.
