The concept of “matters of mutual interest” is used in a number of sections and definitions in the Labour Relations Act 66 of 1995 (LRA). This is an indication that this is an important concept in labour law, and it is therefore imperative that it be properly understood. At times this concept is misunderstood to be synonymous with disputes of interest, however, that is not necessarily the case. This concept is used, for example, in the definitions of both collective agreement and strike contained in section 213 of the LRA. It is also used in section 134 of the LRA which deals with dispute resolution. In spite of its importance, the LRA does not provide a definition for the concept. As a result the interpretation of this concept has raised some challenges as it will be seen from Vanachem Vanadium Products (Pty) Ltd v National Union of Metalworkers of South Africa ([2014] 9 BLLR 923 (LC)). In this matter, the court was required to determine whether certain matters were matters of mutual interest for purposes of strike action. Section 213 of the LRA defines “strike” as: “the partial or complete concerted refusal to work, or the retardation or obstruction of work, by persons who are or have been employed by the same employer or by different employers, for the purpose of remedying a grievance or resolving a dispute in respect of any matter of mutual interest (author’s own emphasis) between employer and employee …”
 Based on the above definition, the purpose of the refusal to work by employees must be to “remedy a grievance” or “resolve a dispute in respect of matters of mutual interest between the employer and employees”. A dispute which does not fall under matters of mutual interest is therefore not covered for purposes of a strike. The correct interpretation of this concept in this context is important as it ultimately determines whether or not a trade union and its members may strike in support of a particular demand. This note will consider the concept of “matters of mutual interest” and the way it has been interpreted and then evaluate the finding in Vanachem Vanadium Products v NUMSA in order to determine whether the court was correct in its determination of whether disputes or demands raised by NUMSA for purposes of a strike were matters of mutual interest or not.