Petahertz frequency bands have a unique characteristic of atmospheric scattering that enables non-line-of-sight (NLOS) communications. In this paper, we analyze the performance of petahertz wireless communications (PWC) with a novel statistical model derived over a multiuser interferencelimited optical turbulence channel. Specifically, we derive a novel probability density function of the received signal-to-interference ratio when the distribution of the received signal is quantified with each scattered path following a Málaga distribution. Moreover, novel closed-form expressions for the outage and the bit error probabilities are derived in the interference-limited PWC. The outage performance is evaluated over non-identical Málaga fading channels, where the fading characteristics of the transmitter and the interferer are different. We also investigate the achievable capacity of the multiuser interference-limited PWC over Málaga fading channels. The analytical results obtained are corroborated with simulation results. It is shown that the analysis performed with the proposed statistical model is reliable and accurate and thus the statistical model can be useful for emerging multiuser interference-limited petahertz wireless communications.INDEX TERMS Optical communications, outage probability, signal-to-interference ratio, turbulence fading.