American Cyanamid Co v Ethicon Ltd [1975] UKHL 1 is an English civil procedure case, concerning when an interim injunction may be obtained.

The House of Lords set out detailed guidelines on when courts should grant interim injunctions.

In this case, the House of Lords decided that the balance of convenience lay with the appellant, American Cyanamid, and the appeal was allowed.

[3] The points in the House of Lords' guidance have subsequently been referred to as the "American Cyanamid principles".

[4] Lord Justice Brown codified them into seven points, listed in Fellowes & Son v Fisher (1976).