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In vitro‐produced embryos exhibit decreased cell numbers, small inner cell masses and reduced pregnancy rates after transfer. Evaluation of intracellular components of in vitro‐produced or ‐manipulated embryos will lead to improved methodology for embryo production. Whole mount techniques were developed to utilize terminal deoxynucleotidyl‐transferase 3′ nick end labeling (TUNEL) to detect broken DNA. Subsequent labeling of either tubulin or actin filaments provides further evidence of cytological damage. Porcine embryos produced in vitro or in vivo were evaluated throughout the cleavage and preimplantation stages of development. Early cleavage stages up to the 8‐cell stage never contained TUNEL‐labeled nuclei. However, TUNEL labeling of in vitro‐produced morula revealed some blastomeres with broken DNA. Nearly all in vitro‐produced blastocysts displayed some TUNEL positive cells …