However, it was placed higher than Indonesia (38th), South Korea (43rd), Cambodia (51st), China (62nd) and Myanmar (68th) in the region, according to the ranking compiled by American media company U.S. News & World Report.
Last year, Vietnam had ranked 35th among 78 destinations.
The company said it based the latest ranking on a global survey of more than 17,000 people recording their perceptions on several factors: affordability, favorable tax environment, friendliness, pleasant climate, respect for property rights and well-developed public health system.
New Zealand ranked first in the list, followed by Switzerland and Spain.
Cheap living costs, high-quality healthcare and low levels of violent crime have made Vietnam a top choice for foreign retirees.
Last August, American magazine Travel+Leisure listed Vietnam as one of eight most ideal countries for Americans to move to after retirement thanks to cheap cost of living and diverse travel experiences.
However, visa hassles remain a major challenge.
While Southeast Asian neighbors are vying hard for wealthy foreign retirees by launching 'golden visas' with maximum stays of 20 years, Vietnam has adopted one-month single-entry visa policy since it reopened its doors to international tourism in mid-March.
Both foreign tourists and Vietnamese travel agencies have said the current policy is functioning as a tourism barrier.
Vietnam is offering visa exemption to 24 countries and territories for a maximum stay of 90 days.