Florida Governor Charlie Crist has signed his first death warrant, ending a seven-month moratorium adopted by the US state after a botched execution.
Executions were halted following the botched death of Angel Diaz
His predecessor, Jeb Bush, suspended lethal injections in late 2006 after a convicted murderer took 34 minutes to die and had to be given a second dose.
Mr Crist said steps had been taken to improve the execution process.
The warrant is for Mark Dean Schwab, sentenced to death in 1992 for kidnap, rape and murder of an 11-year-old boy.
He is scheduled to be executed on 15 November this year.
Schwab's lawyer has argued he should be spared the death penalty so psychiatrists can study him and use what they learn to prevent other paedophiles striking.
Florida was among nine states to have put executions on hold as it evaluated whether death by lethal injection breached a constitutional ban on "cruel and unusual punishment".
US METHODS OF EXECUTION
Lethal injection: Authorised in 37 states (plus US military & federal government)
Electrocution: In 10 states (sole method in Nebraska)
Gas chamber: In five states (all of which have lethal injection as alternative)
Hanging: Only in New Hampshire and Washington
Firing squad: In Idaho and Oklahoma. It is available to inmates in Utah who chose it before the method was banned
Source: Death Penalty Information Center
Mr Bush set up a special commission to evaluate the practice following the drawn-out death by lethal injection of Puerto Rican-born Angel Diaz in December 2006.
Mr Crist said he was confident that "the training, organisation and communication processes" recommended by the panel and adopted by the state in May would ensure the lethal injection process now met requirements.
Lethal injection is the preferred method of execution in 37 US states.
In California, a judge has ruled death by lethal injection violates a state ban on cruel and unusual punishment.
Diaz was sentenced to death for the 1979 murder of a Miami strip club manager.
Witnesses said his death took more than twice the usual time - 34 minutes rather than the usual 15.
Following the autopsy, the medical examiner concluded the injections had been wrongly administered.
His lawyer reported that the 55-year-old continued to move and mouth words more than 20 minutes after the initial dose.
Subjects are supposed to be rendered unconscious by the chemicals within three to five minutes.
Anti-death penalty activists say lethal injections - introduced in Florida and other states as a replacement for the electric chair and other methods of execution - are just as cruel and should not be considered a more humane substitute.