diff --git a/DESCRIPTION b/DESCRIPTION
index 221860da0b664ae9825aaac88dafe38a56f9b7f2..ff1d055a610c3cb7f58eda652bdc6dfc4570595b 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -46,6 +46,7 @@ Suggests:
     knitr,
     rmarkdown,
     shiny,
-    rpanel
+    rpanel,
+    testthat
 VignetteBuilder: knitr
 RoxygenNote: 5.0.1
diff --git a/tests/testthat.R b/tests/testthat.R
new file mode 100644
index 0000000000000000000000000000000000000000..8cd71f9112a79fbfc72247f3e505da7f95a0ec2a
--- /dev/null
+++ b/tests/testthat.R
@@ -0,0 +1,4 @@
+library(testthat)
+library(MRDCr)
+
+test_check("MRDCr")
diff --git a/tests/testthat/test_funprobs.R b/tests/testthat/test_funprobs.R
new file mode 100644
index 0000000000000000000000000000000000000000..96a74ea7379ebf1d18359be56680aea06c7b75ec
--- /dev/null
+++ b/tests/testthat/test_funprobs.R
@@ -0,0 +1,11 @@
+context("Testa as Funções de Probabilidade")
+
+test_that("Iguais a Poisson", {
+    y <- 0:30
+    lambda <- 30 * runif(1)
+    py_pois <- dpois(x = y, lambda = lambda)
+    py_pgnz <- dpgnz(y = y, lambda = lambda, alpha = 0)
+    py_gcnt <- dgcnt(y = y, lambda = lambda, alpha = 1)
+    expect_equal(py_pgnz, py_pois)
+    expect_equal(py_gcnt, py_pois)
+})
diff --git a/tests/testthat/test_logliks.R b/tests/testthat/test_logliks.R
new file mode 100644
index 0000000000000000000000000000000000000000..cd38a8723b331ef396f798dc579e34e801783d39
--- /dev/null
+++ b/tests/testthat/test_logliks.R
@@ -0,0 +1,27 @@
+context("Testa as Funções de Log-Verossimilhança")
+
+test_that("Tem os mesmo argumentos", {
+    apropos("formals")
+    a_gcnt <- as.list(formals(llgcnt))
+    a_pgnz <- as.list(formals(llpgnz))
+    expect_equal(a_gcnt, a_pgnz)
+})
+
+test_that("São iguais a Poisson", {
+    y <- 0:10
+    X <- cbind(y * 0 + 1)
+    lamb <- 10 * runif(1)
+    ll_pois <- -sum(dpois(x = y, lambda = lamb, log = TRUE))
+    ll_pgnz <- llpgnz(params = c(0, log(lamb)), y = y, X = X)
+    ll_gcnt <- llgcnt(params = c(log(1), log(lamb)), y = y, X = X)
+    expect_equal(ll_pgnz, expected = ll_pois)
+    expect_equal(ll_gcnt, expected = ll_pois)
+})
+
+test_that("Inteiros negativos resultam em Warning", {
+    y <- -4:-1
+    X <- cbind(y * 0 + 1)
+    lamb <- 10 * runif(1)
+    expect_warning(llpgnz(params = c(0, log(lamb)), y = y, X = X))
+    expect_warning(llgcnt(params = c(log(1), log(lamb)), y = y, X = X))
+})