The report, published by the Centre for Research on Families and Relationships at the University of Edinburgh, suggests that raising the voice or shouting is the next most effective action.
The report is an analysis of data from the Growing Up in Scotland (GUS) study and comes weeks after MPs voted against enforcing a UK-wide smacking ban.
The GUS study, commissioned by the Scottish Government, surveyed parents of 8,000 children about issues affecting their parenting style.
The survey has shown that fewer than 20 per cent thought smacking was useful when caring for three-year-olds and the proportion was lower for younger children.
Raising the voice or shouting was seen as a useful technique by about a third of main carers and more than 40 per cent of their partners.
Men were no more likely to smack than women and there were no clear links between smacking and age, income, socio-economic status or level of education, although those with no qualifications are more likely to see smacking or shouting as useful among the toddler group.
However, a residual belief in smacking as a last resort seems to exist among fewer than half of those surveyed.
"This report highlights interesting trends, but it is also important to remember that parenting impacts on children is a complex matter and we need to look carefully at claims that there is a 'one size fits all' style of parenting," Timesonline quoted Professor Lynn Jamieson, from the Centre for Research on Families and Relationships, as saying.
"Outcomes for children may be as influenced by social and economic resources as they are by parenting styles. Parenting strategies to ensure a child's wellbeing may need to be very different on a housing estate affected by high levels of drug abuse and violence than those in a middle-class leafy suburb," Jamieson added.