—Experiments and theoretical analysis of influence of temperature on polarization mode dispersion (PMD) in single mode optical fibers and cables are presented. Forces generated by contracting buffer create optical birefringence and increase fiber PMD at low temperatures. Single mode fiber (SMF) in 0.9 mm polymeric tight-buffer can exhibit an extra component of PMD exceeding 0.3 ps/√km in such conditions. On the other hand, tight-buffered spun nonzero dispersion-shifted fibers (NZDSF) and optical units with stranded single mode fibers have showed good stability of PMD over wide range of temperatures. This is due to presence of circular strain in the core, blocking accumulation of mechanically induced birefringence.