diff --git a/irc/commands.go b/irc/commands.go
index 0fa347aa..a0963687 100644
--- a/irc/commands.go
+++ b/irc/commands.go
@@ -54,6 +54,7 @@ var (
 		VERSION: NewVersionCommand,
 		WHO:     NewWhoCommand,
 		WHOIS:   NewWhoisCommand,
+		WHOWAS:  NewWhoWasCommand,
 	}
 )
 
@@ -968,3 +969,26 @@ func NewKillCommand(args []string) (editableCommand, error) {
 		comment:  args[1],
 	}, nil
 }
+
+type WhoWasCommand struct {
+	BaseCommand
+	nicknames []string
+	count     int64
+	target    string
+}
+
+func NewWhoWasCommand(args []string) (editableCommand, error) {
+	if len(args) < 1 {
+		return nil, NotEnoughArgsError
+	}
+	cmd := &WhoWasCommand{
+		nicknames: strings.Split(args[0], ","),
+	}
+	if len(args) > 1 {
+		cmd.count, _ = strconv.ParseInt(args[1], 10, 64)
+	}
+	if len(args) > 2 {
+		cmd.target = args[2]
+	}
+	return cmd, nil
+}
diff --git a/irc/constants.go b/irc/constants.go
index 6b4a89ec..bab17e6b 100644
--- a/irc/constants.go
+++ b/irc/constants.go
@@ -61,6 +61,7 @@ const (
 	VERSION StringCode = "VERSION"
 	WHO     StringCode = "WHO"
 	WHOIS   StringCode = "WHOIS"
+	WHOWAS  StringCode = "WHOWAS"
 
 	// numeric codes
 	RPL_WELCOME           NumericCode = 1
diff --git a/irc/reply.go b/irc/reply.go
index 27b39fa8..a32a5765 100644
--- a/irc/reply.go
+++ b/irc/reply.go
@@ -394,6 +394,16 @@ func (target *Client) RplTime() {
 		"%s :%s", target.server.name, time.Now().Format(time.RFC1123))
 }
 
+func (target *Client) RplWhoWasUser(nickname, username, hostname, realname string) {
+	target.NumericReply(RPL_WHOWASUSER,
+		"%s %s %s * :%s", nickname, username, hostname, realname)
+}
+
+func (target *Client) RplEndOfWhoWas(nickname string) {
+	target.NumericReply(RPL_ENDOFWHOWAS,
+		"%s :End of WHOWAS", nickname)
+}
+
 //
 // errors (also numeric)
 //
@@ -512,3 +522,8 @@ func (target *Client) ErrChannelIsFull(channel *Channel) {
 	target.NumericReply(ERR_CHANNELISFULL,
 		"%s :Cannot join channel (+l)", channel)
 }
+
+func (target *Client) ErrWasNoSuchNick(nickname string) {
+	target.NumericReply(ERR_WASNOSUCHNICK,
+		"%s :There was no such nickname", nickname)
+}
diff --git a/irc/server.go b/irc/server.go
index fa186b0d..d31b0eac 100644
--- a/irc/server.go
+++ b/irc/server.go
@@ -844,6 +844,15 @@ func (msg *KillCommand) HandleServer(server *Server) {
 	target.Quit(quitMsg)
 }
 
+func (msg *WhoWasCommand) HandleServer(server *Server) {
+	client := msg.Client()
+	for _, nickname := range msg.nicknames {
+		// TODO implement nick history
+		client.ErrWasNoSuchNick(nickname)
+		client.RplEndOfWhoWas(nickname)
+	}
+}
+
 //
 // keeping track of clients
 //