Taylor was sentenced by the U.N. Special Court for Sierra Leone in May to 50 years in prison for aiding and abetting crimes against humanity committed by rebel forces in Sierra Leone. He was convicted on 11 counts of war crimes during civil war in the 1990s.
Human Rights Watch, in a 55-page report, said its analysis of the trial found the case was handled fairly and efficiently.
Annie Gell, an international justice fellow at Human Rights Watch, said Taylor's trial indicates prosecution of high-level suspects is possible.
"It was a long road and there was room for improvement, yet the proceedings were relatively well-managed, more than 100 witnesses testified, and expert defense counsel strengthened the proceedings," said Gell, who wrote the report, in a statement from Brussels.
An estimated 50,000 people were killed in the 11-year civil war in Sierra Leone. Taylor, who's issued an appeal, told the tribunal before his sentencing that "reconciliation and healing" should guide the court's principles.
The U.N. Security Council this week lifted sanctions against 17 Liberians linked to the former president, including two of his former wives.