Few pastors give up on their ministry despite intense stress, a leading Christian research company has found.

In a first-of-its-kind study, LifeWay Research surveyed 1,500 pastors in evangelical and historically black churches and found that pastors are relatively stable. The study was commissioned following concern about pastoral mental attrition.

The research found that despite high levels of stress, "pastors are not leaving the ministry in droves," said Scott McConnell, LifeWay Research vice-president.

84 per cent of pastors say they are on call 24 hours a day and 48 per cent reportedly feel the demands of their ministry are more than they can handle.

"This is a brutal job," said McConnell. "The problem isn't that pastors are quitting - the problem is that pastors have a challenging work environment.

"Churches ought to be concerned, and they ought to be doing what they can."

Nevertheless today's pastors are relatively stable; 44 per cent have maintained the position of senior pastor for more than 10 years.

Only a small proportion of previous pastors have quit, current pastors say. Two per cent shifted to non-ministry jobs, and five per cent stayed in ministry but switched to non-pastoral roles. Combined, those two groups account for known losses of less than one per cent a year.

In spite of the stresses, 92 per cent of pastors says their congregations regularly give encouragement to the pastor's family.

H.B. London, pastor to pastors emeritus at Focus on the Family, said: "For a pastor and his family to know that 1) the leadership is praying for them, 2) they affirm them, 3) they encourage them, and 4) they recognize the work that is being done - those are things that give a pastor hope or give a pastor a sense of being wanted."