diff --git a/subsys/bluetooth/controller/ll_sw/ull_conn.c b/subsys/bluetooth/controller/ll_sw/ull_conn.c
index 1506b099abc..c64717edb68 100644
--- a/subsys/bluetooth/controller/ll_sw/ull_conn.c
+++ b/subsys/bluetooth/controller/ll_sw/ull_conn.c
@@ -179,6 +179,19 @@ static uint8_t force_md_cnt_calc(struct lll_conn *lll_conn, uint32_t tx_rate);
 				(LL_LENGTH_OCTETS_TX_MAX + \
 				BT_CTLR_USER_TX_BUFFER_OVERHEAD))
 
+/* Encryption request is enqueued in thread context from the Tx buffer pool,
+ * so that it is serialized alongwith the already enqueued data buffers ensuring
+ * they are transmitted out to peer before encryption is setup.
+ * Allocate additional Tx buffers to accommodate simultaneous encryption setup
+ * across active connections.
+ */
+#if defined(CONFIG_BT_CTLR_LE_ENC)
+#define CONN_ENC_REQ_BUFFERS CONFIG_BT_CTLR_LLCP_CONN
+#else
+#define CONN_ENC_REQ_BUFFERS 0
+#endif
+#define CONN_DATA_BUFFERS (CONFIG_BT_BUF_ACL_TX_COUNT + CONN_ENC_REQ_BUFFERS)
+
 /**
  * One connection may take up to 4 TX buffers for procedures
  * simultaneously, for example 2 for encryption, 1 for termination,
@@ -196,13 +209,14 @@ static uint8_t force_md_cnt_calc(struct lll_conn *lll_conn, uint32_t tx_rate);
 /* CIS Establishment procedure state values */
 #define CIS_REQUEST_AWAIT_HOST 2
 
-static MFIFO_DEFINE(conn_tx, sizeof(struct lll_tx), CONFIG_BT_BUF_ACL_TX_COUNT);
+static MFIFO_DEFINE(conn_tx, sizeof(struct lll_tx), CONN_DATA_BUFFERS);
 static MFIFO_DEFINE(conn_ack, sizeof(struct lll_tx),
-		    (CONFIG_BT_BUF_ACL_TX_COUNT + CONN_TX_CTRL_BUFFERS));
+		    (CONN_DATA_BUFFERS +
+		     CONN_TX_CTRL_BUFFERS));
 
 static struct {
 	void *free;
-	uint8_t pool[CONN_TX_BUF_SIZE * CONFIG_BT_BUF_ACL_TX_COUNT];
+	uint8_t pool[CONN_TX_BUF_SIZE * CONN_DATA_BUFFERS];
 } mem_conn_tx;
 
 static struct {
@@ -213,7 +227,8 @@ static struct {
 static struct {
 	void *free;
 	uint8_t pool[sizeof(memq_link_t) *
-		  (CONFIG_BT_BUF_ACL_TX_COUNT + CONN_TX_CTRL_BUFFERS)];
+		     (CONN_DATA_BUFFERS +
+		      CONN_TX_CTRL_BUFFERS)];
 } mem_link_tx;
 
 #if defined(CONFIG_BT_CTLR_DATA_LENGTH)
@@ -2163,7 +2178,7 @@ static int init_reset(void)
 		 sizeof(conn_pool) / sizeof(struct ll_conn), &conn_free);
 
 	/* Initialize tx pool. */
-	mem_init(mem_conn_tx.pool, CONN_TX_BUF_SIZE, CONFIG_BT_BUF_ACL_TX_COUNT,
+	mem_init(mem_conn_tx.pool, CONN_TX_BUF_SIZE, CONN_DATA_BUFFERS,
 		 &mem_conn_tx.free);
 
 	/* Initialize tx ctrl pool. */
@@ -2172,7 +2187,8 @@ static int init_reset(void)
 
 	/* Initialize tx link pool. */
 	mem_init(mem_link_tx.pool, sizeof(memq_link_t),
-		 CONFIG_BT_BUF_ACL_TX_COUNT + CONN_TX_CTRL_BUFFERS,
+		 (CONN_DATA_BUFFERS +
+		  CONN_TX_CTRL_BUFFERS),
 		 &mem_link_tx.free);
 
 #if !defined(CONFIG_BT_LL_SW_LLCP_LEGACY)