Sir John Wischeard, who succeeded to the lands and barony of Pitarrow in 1576, was another strong Protestant and a leading member of the first congregation against Catholicism. He became a member of the Scottish parliament and the Privy Council in 1560, and distinguished himself against the Earl of Huntly at the battle of Corrichie in 1562.

However, according to John Knox, Queen Mary hated him because "he flattered her not in her dancing and other things".  In 1565, he was denounced as a rebel for opposing the marriage of Queen Mary with Lord Darnley, and was forced to flee to England. The Pitarrow estate was thus forfeited, but restored in the following year after the murder of David Rizzio, when Sir John returned to Scotland and was pardoned. In May 1567, he joined the confederacy against the Earl of Bothwell and was appointed an extraordinary Lord of Session.

The following year Sir John accompanied the Regent Moray to York; but after the battle of Langside he switched his support to the Duke of Chatelherault and, in the cause of Queen Mary, joined Sir William Kirkcaldy as constable of the Castle of Edinburgh. He was one of eight people who supported Kirkcaldy in the siege of Edinburgh Castle until, in 1573, they capitulated to Morton and he was taken prisoner. In 1574 he was re-appointed an extraordinary Lord of Session. After his death in 1576, the Pitarrow estate and title passed to his nephew John Wischeard.

Sir John Wischeard became a member of the Scottish Parliament and, in 1592, was appointed a deputy of the Earl Marischal. He was sent to apprehend the Earl of Huntly and others for the burning of Donibristle and the murder of the Earl of Moray. Sir John married Jean, daughter of William Douglas, 9th Earl of Angus in 1592. In recognition of this important marriage, the Wishart Arms were incorporated in the Douglas Arms; and the Douglas tartan was combined with the Wallace tartan in the design of the Wishart tartan.

Sir John Wischeard was the last important Laird of Pitarrow. After his death in 1607, the estates of Pitarrow and Reidhall passed to his second son James. However, by 1631 James Wishart's affairs had become "embarrassed" and he sold the family's lands at Pitarrow, Carnebeg, Woodtoun and the Mill of Conveth to David, Lord Carnegie for 59,000 merks or £3,277 15s 6d sterling.