Vietnam shares ended at an all-time high on Monday, while most other Southeast Asian markets posted gains as broader Asian stocks climbed on the first trading day of the quarter.
Vietnam stocks rose 1.9 percent to close at an all-time high of 1,196.61, helped by financials and real estate stocks.
Joint Stock Commercial Bank for Foreign Trade of Viet Nam and real estate firm Vingroup JSC climbed 5 percent each, with Vingroup setting a fresh closing record.
Vietnam's steep 21.6 percent rise this year, building on last year's 48 percent gain, has made it Asia's most expensive market in price-to-earnings terms.
Philippine shares recovered from early losses, closing up 0.8 percent, on strength in industrials, as trading resumed after the holidays on Thursday and Friday.
Financial stocks fell after a rights issue of Bank of the Philippine Islands was priced at a 23.5 percent discount to the stock's close on Wednesday. The stock ended 1.7 percent lower in the session.
However, the Philippine market turnover was weak as investors and traders continue to return from the Easter break, said Luis Limlingan, managing director, Regina Capital Development Corp.
Thai shares gained about 0.3 percent as PTT Global Chemical PCL rose 2.1 percent and Kasikornbank ended 1.4 percent higher.
Thailand's annual headline inflation rate picked up in March, but missed forecasts and was below the central bank's target range, giving policymakers leeway to keep monetary policy loose to help economic growth.
Singapore shares edged 0.1 percent higher on real estate and industrials, with Jardine Matheson Holdings Ltd climbing 0.9 percent.
Indonesian shares also rose, boosted by consumer staples and consumer discretionary stocks.
Data showed Indonesia's annual inflation rate accelerated in March compared with a month earlier, but remained well within the central bank's target range.
Astra International Tbk PT climbed 3.4 percent, while Telekomunikasi Indonesia (Persero) rose 1.9 percent.
The index of the country's 45 most liquid stocks gained 1.4 percent.
Meanwhile, Malaysian shares slipped 0.3 percent on losses in telecom stocks and financials, with Malayan Banking Bhd shedding 0.8 percent.