Ulster Bank has reported an operating profit of €752m for the year to the end of December 2014 - its first annual profit since 2008.
This time last year the bank reported a €1.7 billion loss for 2013.
The country's third-largest bank said it was able to write-back the value of some impaired loans by €453m during the year.
It said it was able to do so because of the favourable economic and market conditions here, while it was also supported by rising Irish property values and pro-active debt management.
Ulster Bank also said that investments made to support customers in mortgage arrears has resulted in a sustained reduction since the first quarter of 2013 in the number of customers who have fallen behind in their mortgage repayments for 90 days or more.
The bank, which is owned by Royal Bank of Scotland, said its operating expenses fell by €130m last year. During the last couple of years the bank has closed down several branches all over the country.
Ulster Bank said today that its new lending activity increased by 38% to €2.3 billion, while it also saw a 41% rise in mortgage drawdowns last year.
€1.4 billion of new loan facilities were also made available to its business customers, up 46% on the previous year.
A further €1.9 billion will be made available to business customers this year, the bank said.
The bank's chief executive Jim Brown said the results were a clear signal that its strategy is working and is evidence of sustained progress across all areas of the bank.
"This performance was driven by the underlying strength of the core Ulster Bank franchise and increased lending to customers across personal and business coupled with our proactive debt management and rising asset prices in a recovering economy," he stated.
During the year, Ulster Bank appointed its first Director of Customer Experience and Products, who is responsible for making it easier for customers to do business with it.
"Across the business, we will continue to progress our strategy and build the best bank for customer service on the island of Ireland," Mr Brown said.
Last November, the Central Bank fined Ulster Bank €3.5m in relation to the technology incident in June 2012 which saw customers unable to access their accounts for some weeks.
