This increase was from 27.8 per cent in March, the national statistics office said on Wednesday.
A rise in manufacturing costs boosted by a decline in the cedi currency was the main cause of the increase, although mining and quarrying recorded the biggest single gain, government statistician Philomena Nyarko told a news conference.
"The key drivers are manufacturing of non-metallic products such as cement and food product and beverages," she said.
Producer price inflation is an advance indicator of consumer price inflation, which rose to 14.7 per cent in April driven mainly by imported food items affected by a persistent depreciation of the local currency.
The cedi has slipped around 27 per cent against the dollar since the beginning of the year.
Ghana produces oil, cocoa and gold and is one of Africa's fastest growing economies but the government is struggling to stabilise the country's macro economy and restore fiscal balance.
In particular, it faces a stubbornly high budget deficit, a falling currency, a low current account balance and escalating inflation.