We address propagation of light in nonlinear twisted multi-core fibers with alternating amplifying and absorbing cores that are arranged into the PTsymmetric structure. In this structure, the coupling strength between neighboring cores and global energy transport can be controlled not only by the nonlinearity strength, but also by gain and losses and by the fiber twisting rate. The threshold level of gain/losses, at which PT -symmetry breaking occurs, is a non-monotonic function of the fiber twisting rate and it can be reduced nearly to zero or, instead, notably increased just by changing this rate. Nonlinearity usually leads to the monotonic reduction of the symmetry breaking threshold in such fibers.OCIS codes : (190.5940) (070.7345 The concept of parity-time ( ) PT symmetry that was initially introduced in quantum mechanics [1], has already penetrated into many other areas of science (see [2,3] for recent reviews). Various optical realizations of the PT -symmetric systems, such as couplers, multi-core fibers, shallow photonic lattices, and photonic crystals with inhomogeneous refractive index landscapes obeying the PT symmetry condition ( ) ( ) n n * = -r r , where ( ) n r is the complex refractive index, were suggested. Despite the presence of gain and losses in such systems, the internal currents from amplifying to absorbing domains make it possible for the propagation of the beam without net amplification or attenuation. The most representative property of the PT -symmetric system is the existence of the threshold level of gain/losses, above which the spectrum of the system becomes complex and the propagation of the modes is always accompanied by their amplification or attenuation [4]. The breakup of the PT symmetry was observed experimentally [5,6]. PT -symmetric structures that remain invariable in the direction of light propagation have been used for demonstration of the switching, localization, and nonreciprocal soliton scattering [7][8][9][10][11][12][13]. At the same time, longitudinal variation of the parameters of a PT -symmetric system substantially enrich the spectrum of the available phenomena. Such dynamic structures were used for illustration of the pseudo-PT symmetry [14][15][16] The PT symmetry-breaking threshold depends on several factors, most notably on the size of the system. Usually, this threshold decreases with the increase in the number of elements (for example, waveguides) in the system [22]. However, interesting exceptions are encountered in the discrete circular waveguide arrays, where the threshold changes in a step-like fashion with the increase in the number of waveguides [23,24]. Similar size effects were encountered in complex photonic crystals [25,26]. At the same time, longitudinal modulations of the parameters of the PT -symmetric systems also notably affect the symmetry-breaking threshold [15]. An interesting approach to control the PT -symmetry breaking threshold was introduced in [27], where it was shown that the geometric twist leads to the nonmonotonic variation o...