Introduction: Adding Zinc-salts in fixatives is common with fixating special tissues, such as kidney. However, its effect on other tissues, for example, liver and brain, is still unknown. Objectives: Qualitative and quantitative comparison of the quality of histological staining (nuclei, glycogen, lipids, iron) on liver and brain samples. Comparison of immunohistochemical staining of the brain, after perfusion fixation or immersion fixation with paraformaldehyde (PFA) and/or PFA/Zn solution, is also included. Study design: This is a case-control study (tissues perfused with PFA fixative versus tissues perfused with PFA/Zn fixative, tissues fixated by immersion fixation versus tissues which are perfusion fixated and afterwards immersion fixated. Material and Methods: This study included the liver and brain tissues from 15 rats sorted into 5 groups which are immersion/perfusion fixated with/without zinc-salts. Histological staining used in this study is the following: Hemalaun/eosin, Nissl, oil red, toluidine, toluidine with diastase, toluidine with diastase and additional de-fatting, Perls-DAB. Brain epitopes demonstrated by immunohistochemical processing are the following: NeuN, MAP2, IBA1, GT1b, GFAP and cholera toxin. The results were analysed in computer program Fiji, and then statistically processed. Results: Perfusion with added zinc-salts contributes to increased quality of tissue integrity. There is a statistically significant link between fixation with added zinc-salts and more intensely histologically stained samples, if zinc-salts don't interfere with the chemical reaction as basis for a certain staining. Conclusion: In comparison with routine PFA fixation, fixation with added zinc-salts improves the quality of standard histological and immunohistochemical staining.