The soldier was travelling in an armoured vehicle on a routine mission with Afghan security forces when the bomb detonated at 7.30am, the Swedish Armed Forces (Försvarsmakten) said in a statement.
The Swedish soldier, who comes from Kalmar County in southern Sweden, was treated on the scene by medics who were included in the unit before being evacuated by helicopter back to the Swedish base.
At the time of the incident, the soldier was travelling in a RG-32 mine-resistant armoured vehicle outside the village of Naw Shahr-e-Baluch, 40 kilometres west of Mazar-e-Sharif.
The incident comes a day after a Swedish unit in Afghanistan was fired upon in the same area.
No troops were injured in the Thursday shooting incident, however, which took place around 3pm, as soldiers had disarmed a roadside bomb and were carrying out spot checks of vehicles in the area.
Last year, one Swede employed by the United Nations was killed in an attack in Afghanistan. In 2010, three Swedish troops were killed while serving in the country, along with an Afghan interpreter.
Sweden is in the process of reducing its troop presence in Afghanistan as part of the NATO-led International Security Assistance Force (ISAF).
Sweden's force is expected to shrink to 400 people by the end of 2012, down from some 500 last year.
By 2014, there will be around 200 Swedish troops serving in Afghanistan.