The figure was higher than in the previous two administrations in the impoverished Central American nation of 14 million, said a statement from the Grupo de Apoyo Mutuo (GAM), a non-governmental organization.
Some 14,000 murders were reported from 2000-2004, 21,511 during 2004-2008, and 24,021 from 2008-2012, the statement said.
Guatemala has seen an increase in drug-related violence in recent years, with the growing presence of Mexico`s ultra-violent Zetas drug cartel adding to violence from gangs of youths known as "maras" who control many poor areas.
In 2011, 122 massacres were reported, leaving 466 dead and 152 wounded, the statement said.
In the latest violence, eight people were killed and 20 were wounded overnight Saturday near the capital Guatemala City when assailants sprayed a packed nightclub with gunfire.
Guatemala`s new President Otto Perez, a retired general, has ordered the army to join the fight against drug cartels and organized crime.