This article, based on data from the archives of the Communist security service (SB), presents the surveillance operations in the 1960s and 1970s, which targeted Jewish communists who had belonged to the political elite in the Stalinist years and as a result of the 1956 'thaw' either disappeared from mainstream politics or hung on to relatively inconspicuous posts. Of the reasons for dedicating that particular group to the special attention of the security apparatus none is as important as the demand for material that could be used to incriminate communists of Jewish background. The targeted persons were to have bugs installed in both home and workplace. Their telephone conversations were to be tapped and their letters read; their activities monitored by informers. The surveillance data was to demonstrate the bad character of the members of that group: it would show that they had no qualms about plotting against the official party line, or undermining the authority of the party, or getting involved in 'anti-socialist and Zionist activities'. Undercover operations against prominent communists of Jewish background started in late 1964, after Mieczyslaw Moczar became head of the Ministry of the Interior. They peaked in March 1968 and December 1970, in conjunction with the anti-semitic campaign of 1967-1968 and its aftermath, and were eventually called off in the early 1970s. It was then decided that a decade of investigations had produced no evidence of anti-party activity from that quarter and that the alleged culprits had got too old and obsolescent to have any impact on events.