The Nordic country became the first to ban physical punishment against children under any circumstances, both at home and in school, on March 15, 1979.
Twenty-four other countries have also banned child punishment since then.
Sweden's Children and Parents Code does not carry any penalties but parents are liable to be jailed for between six months and 10 years, depending on the severity of the crime, under Section 5 of the Swedish Penal Code.
In one case in November 2010, a Swedish district court fined a couple US$10,650 (S$13,587) and nine months' jail for spanking three of their four children as part of their "parenting methods".
Former Council of Europe Human Rights Commissioner Thomas Hammarberg was quoted in a 2009 report by non-governmental organisation Save the Children Sweden as saying the prohibition was a means of promoting non-violent methods of child-rearing and protecting their fundamental human right.
The report added that children with violent parents or poor emotional relationships with their caregivers were more likely to have serious psychosocial problems.
A 2000 study noted a reduction in juvenile cases since the introduction of the no-spanking law.
There were 20pc less suicides, 59 per cent less drug use, 48 per cent less rape and 21 per cent less thefts among Swedish youths.
However the study noted that aggravated assault among youths had increased by 54pc.