Organic liquids are frequently used as magnetic resonance (MR) phantom materials. It is often not appreciated that indirect spin-spin coupling can dramatically affect signal amplitudes in spin-echo experiments. These effects are evidenced in three ways: (1) modulation of spin-echo amplitudes; (2) decrease in measured T2 relaxation times; and (3) dependence of spin-echo modulation and measured T2 values on the echo time (TE) in multiecho Carr-Purcell-Meibroom-Gill experiments. This paper illustrates these effects and warns against the inappropriate use of organic liquids as MR phantoms.