Almost 54.6 percent of them forecast a better working quarter, and 34.8 percent forecast their operations will be stable.
Meanwhile, 10.6 percent of businesses say they will face more difficulties than in the first quarter of this year.
The GSO said that the survey questioned 6,500 businesses operating in the processing and manufacturing sector across 63 provinces and cities.
The FDI sector reported the highest rate of enterprises which are optimistic about their business and production situation with 91.3 percent, followed by the non-state sector, and the state sector, with 88.8 percent and 86.8 percent, respectively.
In terms of production volume, 55.7 percent of enterprises forecast increases in the second quarter of 2019, while 10.3 percent predicted decreases.
Half of enterprises say that they will see rises in the number of new orders, while 9.6 percent predict decreases.
The GSO also pointed to several factors affecting business and production activities, including domestic competitiveness, low domestic market demand, and financial difficulties.