Background/Objectives: The latest WHO classification underscores the importance of the complete blood count (CBC) and cell morphology assessment in diagnosing lymphoid neoplasms. This study evaluated the diagnostic role of Research Use Only (RUO) parameters from the BC-6800 Plus Mindray analyzer in differentiating cell chronic lymphocytic leukemia (CLL), acute lymphoblastic leukemia (ALL), and other lymphoproliferative disorders. Methods: CBCs were performed on 90 patients (66% male, median age 67 years) with pathological blood counts (ALL, n=14; CLL, n=47; other lymphoproliferative disorders, n=29) at Novara’s University Hospital. Univariable and multivariable logistic regression assessed the association of basic (WBC, Hb, RDW, NE#, LY#, MO#, PLT) and research cell parameters (NLR, NMR, LMR, NeuX, NeuY, NeuZ, LymX, LymY, LymZ, MonX, MonY, MonZ). Results: In multivariable analysis, Hb (p=0.02), NeuY (p=0.04), and MonY (p=0.01) independently predicted CLL versus ALL, correctly classifying 93.4% of cases (AUC 0.91, 95% CI 0.81-1.0). MO# (p=0.003), LymY (p<0.0001), and MonY (p=0.004) were independent predictors of CLL versus other lymphoproliferative disorders, classifying 77.6% of cases (AUC 0.86, 95% CI 0.78-0.95). NeuZ (p=0.01) and NeuY (p=0.04) independently predicted ALL versus other lymphoproliferative disorders, classifying 93% of cases (AUC 0.98, 95% CI 0.95-1.0). Conclusions: The use of RUO parameters offers valuable, cost-effective support in the early diagnosis of ALL, CLL, and other lymphoproliferative disorders.